           Frequently Asked Questions for FreeBSD 6.X and 7.X

  The FreeBSD Documentation Project

   Copyright (c) 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002,
   2003, 2004, 2005, 2006, 2007, 2008, 2009 The FreeBSD Documentation
   Project

   This is the FAQ for FreeBSD versions 6.X and 7.X. All entries are
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     --------------------------------------------------------------

   Table of Contents

   1 Introduction

   2 Documentation and Support

   3 Installation

   4 Hardware Compatibility

                4.1 General

                4.2 Memory

                4.3 Architectures and Processors

                4.4 Hard Drives, Tape Drives, and CD and DVD Drives

                4.5 Keyboards and Mice

                4.6 Networking and Serial Devices

                4.7 Sound Devices

                4.8 Other Hardware

   5 Troubleshooting

   6 Commercial Applications

   7 User Applications

   8 Kernel Configuration

   9 Disks, File Systems, and Boot Loaders

   10 System Administration

   11 The X Window System and Virtual Consoles

   12 Networking

   13 Security

   14 PPP

   15 Serial Communications

   16 Miscellaneous Questions

   17 The FreeBSD Funnies

   18 Advanced Topics

   19 Acknowledgments

   Bibliography

   List of Tables

   3-1. Maximum File Sizes

   12-1. Network Cards Based on the DEC PCI Chipset

   List of Examples

   11-1. "InputDevice" Section for Wheeled Mouse in Xorg
   Configuration File

   11-2. ".emacs" Example for Naive Page Scrolling with Wheeled Mouse
   (optional)

     --------------------------------------------------------------

                         Chapter 1 Introduction

   Welcome to the FreeBSD 6.X-7.X FAQ!

   As is usual with Usenet FAQs, this document aims to cover the most
   frequently asked questions concerning the FreeBSD operating system
   (and of course answer them!). Although originally intended to
   reduce bandwidth and avoid the same old questions being asked over
   and over again, FAQs have become recognized as valuable
   information resources.

   Every effort has been made to make this FAQ as informative as
   possible; if you have any suggestions as to how it may be
   improved, please feel free to mail them to the FreeBSD
   documentation project mailing list.

   1.1. What is FreeBSD?

   1.2. What is the goal of the FreeBSD Project?

   1.3. Does the FreeBSD license have any restrictions?

   1.4. Can FreeBSD replace my current operating system?

   1.5. Why is it called FreeBSD?

   1.6. What are the differences between FreeBSD and NetBSD, OpenBSD,
   and other open source BSD operating systems?

   1.7. What is the latest version of FreeBSD?

   1.8. What is FreeBSD-CURRENT?

   1.9. What is the FreeBSD-STABLE concept?

   1.10. When are FreeBSD releases made?

   1.11. Who is responsible for FreeBSD?

   1.12. Where can I get FreeBSD?

   1.13. How do I access the Problem Report database?

   1.14. What other sources of information are there?

   1.1. What is FreeBSD?

   Briefly, FreeBSD is a UNIX(R) like operating system for AMD64 and
   Intel(R) EM64T, i386(TM) PC-98, IA-64, ARM(R), PowerPC(R) and
   UltraSPARC(R) platforms based on U.C. Berkeley's "4.4BSD-Lite"
   release, with some "4.4BSD-Lite2" enhancements. It is also based
   indirectly on William Jolitz's port of U.C. Berkeley's "Net/2" to
   the i386, known as "386BSD", though very little of the 386BSD code
   remains. A fuller description of what FreeBSD is and how it can
   work for you may be found on the FreeBSD home page.

   FreeBSD is used by companies, Internet Service Providers,
   researchers, computer professionals, students and home users all
   over the world in their work, education and recreation.

   For more detailed information on FreeBSD, please see the FreeBSD
   Handbook.

   1.2. What is the goal of the FreeBSD Project?

   The goal of the FreeBSD Project is to provide software that may be
   used for any purpose and without strings attached. Many of us have
   a significant investment in the code (and project) and would
   certainly not mind a little financial compensation now and then,
   but we definitely do not insist on it. We believe that our first
   and foremost "mission" is to provide code to any and all comers,
   and for whatever purpose, so that the code gets the widest
   possible use and provides the widest possible benefit. This is, we
   believe, one of the most fundamental goals of Free Software and
   one that we enthusiastically support.

   That code in our source tree which falls under the GNU General
   Public License (GPL) or GNU Library General Public License (LGPL)
   comes with slightly more strings attached, though at least on the
   side of enforced access rather than the usual opposite. Due to the
   additional complexities that can evolve in the commercial use of
   GPL software, we do, however, endeavor to replace such software
   with submissions under the more relaxed FreeBSD license whenever
   possible.

   1.3. Does the FreeBSD license have any restrictions?

   Yes. Those restrictions do not control how you use the code,
   merely how you treat the FreeBSD Project itself. If you have
   serious license concerns, read the actual license. For the simply
   curious, the license can be summarized like this.

     * Do not claim that you wrote this.

     * Do not sue us if it breaks.

   1.4. Can FreeBSD replace my current operating system?

   For most people, yes. But this question is not quite that
   cut-and-dried.

   Most people do not actually use an operating system. They use
   applications. The applications are what really use the operating
   system. FreeBSD is designed to provide a robust and full-featured
   environment for applications. It supports a wide variety of web
   browsers, office suites, email readers, graphics programs,
   programming environments, network servers, and just about
   everything else you might want. Most of these applications can be
   managed through the Ports Collection.

   If you need to use an application that is only available on one
   operating system, you simply cannot replace that operating system.
   Chances are there is a very similar application on FreeBSD,
   however. If you want a solid office or Internet server, a reliable
   workstation, or just the ability to do your job without
   interruptions, FreeBSD will almost certainly do everything you
   need. Many computer users across the world, including both novices
   and experienced UNIX administrators, use FreeBSD as their only
   desktop operating system.

   If you are migrating to FreeBSD from some other UNIX environment,
   you already know most of what you need to. If your background is
   in graphic-driven operating systems such as Windows(R) and older
   versions of Mac OS(R), expect to invest additional time learning
   the UNIX way of doing things. This FAQ and the FreeBSD Handbook
   are excellent places to start.

   1.5. Why is it called FreeBSD?

   * It may be used free of charge, even by commercial users.

   * Full source for the operating system is freely available, and
     the minimum possible restrictions have been placed upon its use,
     distribution and incorporation into other work (commercial or
     non-commercial).

   * Anyone who has an improvement or bug fix is free to submit their
     code and have it added to the source tree (subject to one or two
     obvious provisions).

   It is worth pointing out that the word "free" is being used in two
   ways here, one meaning "at no cost", the other meaning "you can do
   whatever you like". Apart from one or two things you cannot do
   with the FreeBSD code, for example pretending you wrote it, you
   can really do whatever you like with it.

   1.6. What are the differences between FreeBSD and NetBSD, OpenBSD,
   and other open source BSD operating systems?

   James Howard wrote a good explanation of the history and
   differences between the various projects for DaemonNews, called
   The BSD Family Tree which goes a fair way to answering this
   question.

   1.7. What is the latest version of FreeBSD?

   At this point in FreeBSD's development, there are two parallel
   development branches; releases are being made from both branches.
   The 6.X series of releases is being made from the 6-STABLE branch
   and the 7.X series of releases from 7-STABLE.

   Up until the release of 7.0, the 6.X series was the one known as
   -STABLE. However, as of 7.0, the 6.X branch will be designated for
   an "extended support" status and receive only fixes for major
   problems, such as security-related fixes. There will be more
   releases made from the 6-STABLE branch, but it is considered a
   "legacy" branch and most current work will only become a part of
   7-STABLE.

   Version 8.0 is the latest release from the 7-STABLE branch; it was
   released in Oct 2009. Version 7.2 is the latest release from the
   6-STABLE branch; it was released in May 2009.

   Briefly, -STABLE is aimed at the ISP, corporate user, or any user
   who wants stability and a minimal number of changes compared to
   the new (and possibly unstable) features of the latest -CURRENT
   snapshot. Releases can come from either branch, but -CURRENT
   should only be used if you are prepared for its increased
   volatility (relative to -STABLE, that is).

   Releases are made every few months. While many people stay more
   up-to-date with the FreeBSD sources (see the questions on
   FreeBSD-CURRENT and FreeBSD-STABLE) than that, doing so is more of
   a commitment, as the sources are a moving target.

   More information on FreeBSD releases can be found on the Release
   Engineering page on the FreeBSD Web site.

   1.8. What is FreeBSD-CURRENT?

   FreeBSD-CURRENT is the development version of the operating
   system, which will in due course become the new FreeBSD-STABLE
   branch. As such, it is really only of interest to developers
   working on the system and die-hard hobbyists. See the relevant
   section in the Handbook for details on running -CURRENT.

   If you are not familiar with the operating system or are not
   capable of identifying the difference between a real problem and a
   temporary problem, you should not use FreeBSD-CURRENT. This branch
   sometimes evolves quite quickly and can be un-buildable sometimes.
   People that use FreeBSD-CURRENT are expected to be able to analyze
   any problems and only report them if they are deemed to be
   mistakes rather than "glitches". Questions such as "make world
   produces some error about groups" on the FreeBSD-CURRENT mailing
   list may be treated with contempt.

   Every month, snapshot releases are made based on the current state
   of the -CURRENT and -STABLE branches. The goals behind each
   snapshot release are:

     * To test the latest version of the installation software.

     * To give people who would like to run -CURRENT or -STABLE but
       who do not have the time or bandwidth to follow it on a
       day-to-day basis an easy way of bootstrapping it onto their
       systems.

     * To preserve a fixed reference point for the code in question,
       just in case we break something really badly later. (Although
       CVS normally prevents anything horrible like this happening.)

     * To ensure that all new features and fixes in need of testing
       have the greatest possible number of potential testers.

   No claims are made that any -CURRENT snapshot can be considered
   "production quality" for any purpose. If you want to run a stable
   and fully tested system, you will have to stick to full releases,
   or use the -STABLE snapshots.

   Snapshot releases are directly available from snapshot.

   Official snapshots are generated each month on a regular basis for
   all actively developed branches. There are also daily snapshot
   builds of the popular i386 and amd64 branches, hosted on
   http://snapshots.us.freebsd.org/.

   1.9. What is the FreeBSD-STABLE concept?

   Back when FreeBSD 2.0.5 was released, FreeBSD development branched
   in two. One branch was named -STABLE, one -CURRENT. FreeBSD-STABLE
   is intended for Internet Service Providers and other commercial
   enterprises for whom sudden shifts or experimental features are
   quite undesirable. It receives only well-tested bug fixes and
   other small incremental enhancements. FreeBSD-CURRENT, on the
   other hand, has been one unbroken line since 2.0 was released,
   leading towards 8.0-RELEASE and beyond. For more detailed
   information on branches see "FreeBSD Release Engineering: Creating
   the Release Branch", the status of the branches and the upcoming
   release schedule can be found on the Release Engineering
   Information page.

   The 2.2-STABLE branch was retired with the release of 2.2.8. The
   3-STABLE branch has ended with the release of 3.5.1, the final 3.X
   release. The 4-STABLE branch has ended with the release of 4.11,
   the final 4.X release. The only changes made to either of these
   branches will be, for the most part, security-related bug fixes.
   Support for the 5-STABLE branches has ended with the release of
   5.5, the final 5.X release. Support for the 6-STABLE branches will
   continue for some time but focus primarily on security-related bug
   fixes and other serious issues.

   8.0-STABLE is the actively developed -STABLE branch. The latest
   release on the 8.0-STABLE branch is 8.0-RELEASE, which was
   released in Oct 2009.

   The 8-CURRENT branch is the actively developed -CURRENT branch
   toward the next generation of FreeBSD. See What is
   FreeBSD-CURRENT? for more information on this branch.

   1.10. When are FreeBSD releases made?

   The Release Engineering Team <re@FreeBSD.org> releases a new major
   version of FreeBSD about every 18 months and a new minor version
   about every 8 months, on average. Release dates are announced well
   in advance, so that the people working on the system know when
   their projects need to be finished and tested. A testing period
   precedes each release, in order to ensure that the addition of new
   features does not compromise the stability of the release. Many
   users regard this caution as one of the best things about FreeBSD,
   even though waiting for all the latest goodies to reach -STABLE
   can be a little frustrating.

   More information on the release engineering process (including a
   schedule of upcoming releases) can be found on the release
   engineering pages on the FreeBSD Web site.

   For people who need or want a little more excitement, binary
   snapshots are made daily as discussed above.

   1.11. Who is responsible for FreeBSD?

   The key decisions concerning the FreeBSD project, such as the
   overall direction of the project and who is allowed to add code to
   the source tree, are made by a core team of 9 people. There is a
   much larger team of more than 350 committers who are authorized to
   make changes directly to the FreeBSD source tree.

   However, most non-trivial changes are discussed in advance in the
   mailing lists, and there are no restrictions on who may take part
   in the discussion.

   1.12. Where can I get FreeBSD?

   Every significant release of FreeBSD is available via anonymous
   FTP from the FreeBSD FTP site:

     * The latest 7-STABLE release, 8.0-RELEASE can be found in the
       8.0-RELEASE directory.

     * Snapshot releases are made monthly for the -CURRENT and
       -STABLE branch, these being of service purely to bleeding-edge
       testers and developers.

     * The latest 6-STABLE release, 7.2-RELEASE can be found in the
       7.2-RELEASE directory.

   Information about obtaining FreeBSD on CD, DVD, and other media
   can be found in the Handbook.

   1.13. How do I access the Problem Report database?

   The Problem Report database of all user change requests may be
   queried by using our web-based PR query interface.

   The send-pr(1) command can be used to submit problem reports and
   change requests via electronic mail. Alternatively, the web-based
   problem report submission interface can be used to submit problem
   reports through a web browser.

   Before submitting a problem report, please read Writing FreeBSD
   Problem Reports, an article on how to write good problem reports.

   1.14. What other sources of information are there?

   Please check the Documentation list on the main FreeBSD web site.

     --------------------------------------------------------------

                  Chapter 2 Documentation and Support

   2.1. What good books are there about FreeBSD?

   2.2. Is the documentation available in other formats, such as
   plain text (ASCII), or PostScript?

   2.3. Where do I find info on the FreeBSD mailing lists?

   2.4. What FreeBSD news groups are available?

   2.5. Are there FreeBSD IRC (Internet Relay Chat) channels?

   2.6. Where can I get commercial FreeBSD training and support?

   2.1. What good books are there about FreeBSD?

   The project produces a wide range of documentation, available
   online from this link: http://www.FreeBSD.org/docs.html. In
   addition, the Bibliography at the end of this FAQ, and the one in
   the Handbook reference other recommended books.

   2.2. Is the documentation available in other formats, such as
   plain text (ASCII), or PostScript?

   Yes. The documentation is available in a number of different
   formats and compression schemes on the FreeBSD FTP site, in the
   /pub/FreeBSD/doc/ directory.

   The documentation is categorized in a number of different ways.
   These include:

     * The document's name, such as faq, or handbook.

     * The document's language and encoding. These are based on the
       locale names you will find under /usr/share/locale on your
       FreeBSD system. The current languages and encodings that we
       have for documentation are as follows:

             Name                      Meaning                 
       en_US.ISO8859-1  English (United States)                
       bn_BD.ISO10646-1 Bengali or Bangla (Bangladesh)         
       da_DK.ISO8859-1  Danish (Denmark)                       
       de_DE.ISO8859-1  German (Germany)                       
       el_GR.ISO8859-7  Greek (Greece)                         
       es_ES.ISO8859-1  Spanish (Spain)                        
       fr_FR.ISO8859-1  French (France)                        
       hu_HU.ISO8859-2  Hungarian (Hungary)                    
       it_IT.ISO8859-15 Italian (Italy)                        
       ja_JP.eucJP      Japanese (Japan, EUC encoding)         
       mn_MN.UTF-8      Mongolian (Mongolia, UTF-8 encoding)   
       nl_NL.ISO8859-1  Dutch (Netherlands)                    
       no_NO.ISO8859-1  Norwegian (Norway)                     
       pl_PL.ISO8859-2  Polish (Poland)                        
       pt_BR.ISO8859-1  Portuguese (Brazil)                    
       ru_RU.KOI8-R     Russian (Russia, KOI8-R encoding)      
       sr_YU.ISO8859-2  Serbian (Serbia)                       
       tr_TR.ISO8859-9  Turkish (Turkey)                       
       zh_CN.GB2312     Simplified Chinese (China, GB2312      
                        encoding)                              
       zh_TW.Big5       Traditional Chinese (Taiwan, Big5      
                        encoding)                              

         Note: Some documents may not be available in all languages.

     * The document's format. We produce the documentation in a
       number of different output formats. Each format has its own
       advantages and disadvantages. Some formats are better suited
       for online reading, while others are meant to be aesthetically
       pleasing when printed on paper. Having the documentation
       available in any of these formats ensures that our readers
       will be able to read the parts they are interested in, either
       on their monitor, or on paper after printing the documents.
       The currently available formats are:

         Format                     Meaning                    
       html-split A collection of small, linked, HTML files.   
       html       One large HTML file containing the entire    
                  document                                     
       pdb        Palm Pilot database format, for use with the 
                  iSilo reader.                                
       pdf        Adobe's Portable Document Format             
       ps         PostScript                                   
       rtf        Microsoft's Rich Text Format                 
       txt        Plain text                                   

         Note: Page numbers are not automatically updated when
         loading Rich Text Format into Word. Press Ctrl+A, Ctrl+End,
         F9 after loading the document, to update the page numbers.

     * The compression and packaging scheme. There are three of these
       currently in use.

         1. Where the format is html-split, the files are bundled up
            using tar(1). The resulting .tar file is then compressed
            using the compression schemes detailed in the next point.

         2. All the other formats generate one file, called
            type.format (i.e., article.pdf, book.html, and so on).

            These files are then compressed using two compression
            schemes.

            Scheme                 Description                  
                   The zip format. If you want to uncompress    
            zip    this on FreeBSD you will need to install the 
                   archivers/unzip port first.                  
                   The bzip2 format. Less widespread than zip,  
            bz2    but generally gives smaller files. Install   
                   the archivers/bzip2 port to uncompress these 
                   files.                                       

            So the PostScript version of the Handbook, compressed
            using bzip2 will be stored in a file called book.ps.bz2
            in the handbook/ directory.

   After choosing the format and compression mechanism that you want
   to download, you will have to download the compressed files
   yourself, uncompress them, and then copy the appropriate documents
   into place.

   For example, the split HTML version of the FAQ, compressed using
   bzip2(1), can be found in the
   doc/en_US.ISO8859-1/books/faq/book.html-split.tar.bz2 file. To
   download and uncompress that file you would have to do this.

 # fetch ftp://ftp.FreeBSD.org/pub/FreeBSD/doc/en_US.ISO8859-1/books/faq/book.html-split.tar.bz2
 # bzip2 -d book.html-split.tar.bz2
 # tar xvf book.html-split.tar

   You will be left with a collection of .html files. The main one is
   called index.html, which will contain the table of contents,
   introductory material, and links to the other parts of the
   document. You can then copy or move these to their final location
   as necessary.

   2.3. Where do I find info on the FreeBSD mailing lists?

   You can find full information in the Handbook entry on
   mailing-lists.

   2.4. What FreeBSD news groups are available?

   You can find full information in the Handbook entry on newsgroups.

   2.5. Are there FreeBSD IRC (Internet Relay Chat) channels?

   Yes, most major IRC networks host a FreeBSD chat channel:

     * Channel #FreeBSD on EFNet is a FreeBSD forum, but do not go
       there for tech support or try to get folks there to help you
       avoid the pain of reading manual pages or doing your own
       research. It is a chat channel, first and foremost, and topics
       there are just as likely to involve sex, sports or nuclear
       weapons as they are FreeBSD. You Have Been Warned! Available
       at server irc.efnet.org.

     * Channel #FreeBSDhelp on EFNet is a channel dedicated to
       helping FreeBSD users. They are much more sympathetic to
       questions than #FreeBSD is.

     * Channel ##FreeBSD on Freenode is a general help channel with
       many users at any time. The conversations have been known to
       run off-topic for a while, but priority is given to users with
       FreeBSD questions. We are good about helping you understand
       the basics, referring to the Handbook whenever possible, and
       directing you where to learn more about the topic you need
       help with. We are a primarily English speaking channel, though
       we have users from all over the world. If you would like to
       speak in your native language, try to ask the question in
       English and then relocate to another channel ##freebsd-lang as
       appropriate.

     * Channel #FreeBSD on DALNET is available at irc.dal.net in the
       US and irc.eu.dal.net in Europe.

     * Channel #FreeBSDHelp on DALNET is available at irc.dal.net in
       the US and irc.eu.dal.net in Europe.

     * Channel #FreeBSD on UNDERNET is available at us.undernet.org
       in the US and eu.undernet.org in Europe. Since it is a help
       channel, be prepared to read the documents you are referred
       to.

     * Channel #FreeBSD on RUSNET is a russian-language oriented
       channel dedicated to helping FreeBSD users. This is also good
       place for non-technical discussions.

     * Channel #bsdchat on Freenode is a Traditional-Chinese (UTF-8
       encoding) language oriented channel dedicated to helping
       FreeBSD users. This is also good place for non-technical
       discussions.

   Each of these channels are distinct and are not connected to each
   other. Their chat styles also differ, so you may need to try each
   to find one suited to your chat style. As with all types of IRC
   traffic, if you are easily offended or cannot deal with lots of
   young people (and more than a few older ones) doing the verbal
   equivalent of jello wrestling, do not even bother with it.

   2.6. Where can I get commercial FreeBSD training and support?

   DaemonNews provides commercial training and support for FreeBSD.
   More information can be found at their BSD Mall site.

   The FreeBSD Mall provides commercial FreeBSD support. You can get
   more information at their web site.

   BSD Certification Group, Inc. provides system administration
   certifications for DragonFly BSD, FreeBSD, NetBSD, OpenBSD. If you
   are interested in them, visit their site.

   Any other organizations providing training and support should
   contact the Project in order to be listed here.

     --------------------------------------------------------------

                         Chapter 3 Installation

   Nik Clayton

   3.1. Which file do I download to get FreeBSD?

   3.2. What do I do if the floppy images does not fit on a single
   floppy?

   3.3. Where are the instructions for installing FreeBSD?

   3.4. What do I need in order to run FreeBSD?

   3.5. How can I make my own custom install floppy?

   3.6. Can I have more than one operating system on my PC?

   3.7. Can Windows co-exist with FreeBSD?

   3.8. Windows killed my boot manager! How do I get it back?

   3.9. My A, T, or X series IBM Thinkpad locks up when I first
   booted up my FreeBSD installation. How can I solve this?

   3.10. Can I install on a disk with bad blocks?

   3.11. Strange things happen when I boot the install floppy! What
   is happening?

   3.12. I booted from my ATAPI CD-ROM, but the install program says
   no CD-ROM is found. Where did it go?

   3.13. Can I install on my laptop over PLIP (Parallel Line IP)?

   3.14. Which geometry should I use for a disk drive?

   3.15. Are there any restrictions on how I divide the disk up?

   3.16. Is FreeBSD compatible with any disk managers?

   3.17. When I boot FreeBSD for the first time after install I get
   "Missing Operating System". What is happening?

   3.18. Why can I not get past the boot manager's F? prompt?

   3.19. Do I need to install the complete sources?

   3.20. Do I need to build a kernel?

   3.21. Should I use DES, Blowfish, or MD5 passwords and how do I
   specify which form my users receive?

   3.22. Why does the boot floppy start, but hang at the Probing
   Devices... screen?

   3.23. Why do I get a "panic: can't mount root" error when
   rebooting the system after installation?

   3.24. What are the limits for memory?

   3.25. What are the limits for FFS file systems?

   3.26. Why do I get an error message, "archsw.readin.failed" after
   compiling and booting a new kernel?

   3.27. Installation crashes while booting, what can I do?

   3.1. Which file do I download to get FreeBSD?

   You need three floppy images: floppies/boot.flp,
   floppies/kern1.flp, and floppies/kern2.flp. These images need to
   be copied onto floppies by tools like fdimage or dd(1).

   If you need to download the distributions yourself (for a DOS file
   system install, for instance), below are some recommendations for
   distributions to grab:

     * base/

     * manpages/

     * compat*/

     * doc/

     * src/ssys.*

   Full instructions on this procedure and a little bit more about
   installation issues in general can be found in the Handbook entry
   on installing FreeBSD.

   3.2. What do I do if the floppy images does not fit on a single
   floppy?

   A 3.5 inch (1.44 MB) floppy can accommodate 1,474,560 bytes of
   data. The boot image is exactly 1,474,560 bytes in size.

   Common mistakes when preparing the boot floppy are:

     * Not downloading the floppy image in binary mode when using
       FTP.

       Some FTP clients default their transfer mode to ascii and
       attempt to change any end-of-line characters received to match
       the conventions used by the client's system. This will almost
       invariably corrupt the boot image. Check the size of the
       downloaded boot image: if it is not exactly that on the
       server, then the download process is suspect.

       To workaround: type binary at the FTP command prompt after
       getting connected to the server and before starting the
       download of the image.

     * Using the DOS copy command (or equivalent GUI tool) to
       transfer the boot image to floppy.

       Programs like copy will not work as the boot image has been
       created to be booted into directly. The image has the complete
       content of the floppy, track for track, and is not meant to be
       placed on the floppy as a regular file. You have to transfer
       it to the floppy "raw", using the low-level tools (e.g.
       fdimage or rawrite) described in the installation guide to
       FreeBSD.

   3.3. Where are the instructions for installing FreeBSD?

   Installation instructions can be found in the Handbook entry on
   installing FreeBSD.

   3.4. What do I need in order to run FreeBSD?

   For FreeBSD you will need a 486 or better PC, with 24 MB or more
   of RAM and at least 150 MB of hard disk space.

   All versions of FreeBSD can run with a low end MDA graphics card
   but to run Xorg, a VGA or better video card is needed.

   See also Chapter 4.

   3.5. How can I make my own custom install floppy?

   Currently there is no way to just make a custom install floppy.
   You have to cut a whole new release, which will include your
   install floppy.

   To make a custom release, follow the instructions in the Release
   Engineering article.

   3.6. Can I have more than one operating system on my PC?

   Have a look at the multi-OS page.

   3.7. Can Windows co-exist with FreeBSD?

   Install Windows first, then FreeBSD. FreeBSD's boot manager will
   then manage to boot Windows and FreeBSD. If you install Windows
   second, it will boorishly overwrite your boot manager without even
   asking. If that happens, see the next section.

   3.8. Windows killed my boot manager! How do I get it back?

   You can reinstall the boot manager FreeBSD comes with in one of
   three ways:

     * Running DOS, go into the tools directory of your FreeBSD
       distribution and look for bootinst.exe. You run it like so:

 ...\TOOLS> bootinst.exe boot.bin

       and the boot manager will be reinstalled.

     * Boot the FreeBSD boot floppy again and go to the Custom menu
       item for custom installation. Choose Partition. Select the
       drive which used to contain your boot manager (likely the
       first one) and when you come to the partition editor for it,
       as the very first thing (e.g. do not make any changes) press
       W. This will ask for confirmation, select [ Yes ], and when
       you get the Boot Manager selection prompt, be sure to select
       the FreeBSD Boot Manager. This will re-write the boot manager
       to disk. Now quit out of the installation menu and reboot off
       the hard disk as normal.

     * Boot the FreeBSD boot floppy (or CD-ROM) and choose the Fixit
       menu item. Select either the Fixit floppy or CD-ROM #2 (the
       "live" file system option) as appropriate and enter the fixit
       shell. Then execute the following command:

 Fixit# fdisk -B -b /boot/boot0 bootdevice

       substituting bootdevice for your real boot device such as ad0
       (first IDE disk), ad4 (first IDE disk on auxiliary
       controller), da0 (first SCSI disk), etc.

   3.9. My A, T, or X series IBM Thinkpad locks up when I first
   booted up my FreeBSD installation. How can I solve this?

   A bug in early revisions of IBM's BIOS on these machines
   mistakenly identifies the FreeBSD partition as a potential FAT
   suspend-to-disk partition. When the BIOS tries to parse the
   FreeBSD partition it hangs.

   According to IBM[1], the following model/BIOS release numbers
   incorporate the fix.

              Model                        BIOS revision              
   T20                         IYET49WW or later                      
   T21                         KZET22WW or later                      
   A20p                        IVET62WW or later                      
   A20m                        IWET54WW or later                      
   A21p                        KYET27WW or later                      
   A21m                        KXET24WW or later                      
   A21e                        KUET30WW                               

   It has been reported that later IBM BIOS revisions may have
   reintroduced the bug. This message from Jacques Vidrine
   <nectar@FreeBSD.org> to the FreeBSD laptop computer mailing list
   describes a procedure which may work if your newer IBM laptop does
   not boot FreeBSD properly, and you can upgrade or downgrade the
   BIOS.

   If you have an earlier BIOS, and upgrading is not an option, a
   workaround is to install FreeBSD, change the partition ID FreeBSD
   uses, and install new boot blocks that can handle the different
   partition ID.

   First, you will need to restore the machine to a state where it
   can get through its self-test screen. Doing this requires powering
   up the machine without letting it find a FreeBSD partition on its
   primary disk. One way is to remove the hard disk and temporarily
   move it to an older ThinkPad (such as a ThinkPad 600) or a desktop
   PC with an appropriate conversion cable. Once it is there, you can
   delete the FreeBSD partition and move the hard disk back. The
   ThinkPad should now be in a bootable state again.

   With the machine functional again, you can use the workaround
   procedure described here to get a working FreeBSD installation.

    1. Download boot1 and boot2 from
       http://people.FreeBSD.org/~bmah/ThinkPad/. Put these files
       somewhere you will be able to retrieve them later.

    2. Install FreeBSD as normal on to the ThinkPad. Do not use
       Dangerously Dedicated mode. Do not reboot when the install has
       finished.

    3. Either switch to the "Emergency Holographic Shell" (Alt+F4) or
       start a "fixit" shell.

    4. Use fdisk(8) to change the FreeBSD partition ID from 165 to
       166 (this is the type used by OpenBSD).

    5. Bring the boot1 and boot2 files to the local file system.

    6. Use disklabel(8) to write boot1 and boot2 to your FreeBSD
       slice.

 # disklabel -B -b boot1 -s boot2 ad0sn

       n is the number of the slice where you installed FreeBSD.

    7. Reboot. At the boot prompt you will be given the option of
       booting OpenBSD. This will actually boot FreeBSD.

   Getting this to work in the case where you want to dual boot
   OpenBSD and FreeBSD on the same laptop is left as an exercise for
   the reader.

   3.10. Can I install on a disk with bad blocks?

   You can, but it is a bad idea.

   If you are seeing bad block errors with a modern IDE drive,
   chances are the drive is going to die very soon (the drive's
   internal remapping functions are no longer sufficient to fix the
   bad blocks, which means the disk is heavily corrupted); we suggest
   you buy a new hard drive.

   If you have a SCSI drive with bad blocks, see this answer.

   3.11. Strange things happen when I boot the install floppy! What
   is happening?

   If you are seeing things like the machine grinding to a halt or
   spontaneously rebooting when you try to boot the install floppy,
   here are three questions to ask yourself:

    1. Did you use a new, freshly-formatted, error-free floppy
       (preferably a brand-new one straight out of the box, as
       opposed to the magazine cover disk that has been lying under
       the bed for the last three years)?

    2. Did you download the floppy image in binary (or image) mode?
       (do not be embarrassed, even the best of us have accidentally
       downloaded a binary file in ASCII mode at least once!)

    3. If you are using Windows 95 or Windows 98 did you run fdimage
       or rawrite in pure DOS mode? These operating systems can
       interfere with programs that write directly to hardware, which
       the disk creation program does; even running it inside a DOS
       shell in the GUI can cause this problem.

   There have also been reports of Netscape(R) causing problems when
   downloading the boot floppy, so it is probably best to use a
   different FTP client if you can.

   3.12. I booted from my ATAPI CD-ROM, but the install program says
   no CD-ROM is found. Where did it go?

   The usual cause of this problem is a mis-configured CD-ROM drive.
   Many PCs now ship with the CD-ROM as the slave device on the
   secondary IDE controller, with no master device on that
   controller. This is illegal according to the ATAPI specification,
   but Windows plays fast and loose with the specification, and the
   BIOS ignores it when booting. This is why the BIOS was able to see
   the CD-ROM to boot from it, but why FreeBSD cannot see it to
   complete the install.

   Reconfigure your system so that the CD-ROM is either the master
   device on the IDE controller it is attached to, or make sure that
   it is the slave on an IDE controller that also has a master
   device.

   3.13. Can I install on my laptop over PLIP (Parallel Line IP)?

   Yes. Use a standard Laplink cable. If necessary, you can check out
   the PLIP section of the Handbook for details on parallel port
   networking.

   3.14. Which geometry should I use for a disk drive?

   Note: By the "geometry" of a disk, we mean the number of
   cylinders, heads and sectors/track on a disk. We will refer to
   this as C/H/S for convenience. This is how the PC's BIOS works out
   which area on a disk to read/write from.

   This causes a lot of confusion among new system administrators.
   First of all, the physical geometry of a SCSI drive is totally
   irrelevant, as FreeBSD works in term of disk blocks. In fact,
   there is no such thing as "the" physical geometry, as the sector
   density varies across the disk. What manufacturers claim is the
   "physical geometry" is usually the geometry that they have
   determined wastes the least space. For IDE disks, FreeBSD does
   work in terms of C/H/S, but all modern drives internally convert
   this into block references.

   All that matters is the logical geometry. This is the answer that
   the BIOS gets when it asks the drive "what is your geometry?" It
   then uses this geometry to access the disk. As FreeBSD uses the
   BIOS when booting, it is very important to get this right. In
   particular, if you have more than one operating system on a disk,
   they must all agree on the geometry. Otherwise you will have
   serious problems booting!

   For SCSI disks, the geometry to use depends on whether extended
   translation support is turned on in your controller (this is often
   referred to as "support for DOS disks >1GB" or something similar).
   If it is turned off, then use N cylinders, 64 heads and 32
   sectors/track, where N is the capacity of the disk in MB. For
   example, a 2 GB disk should pretend to have 2048 cylinders, 64
   heads and 32 sectors/track.

   If it is turned on (it is often supplied this way to get around
   certain limitations in MS-DOS(R)) and the disk capacity is more
   than 1 GB, use M cylinders, 63 sectors per track (not 64), and 255
   heads, where M is the disk capacity in MB divided by 7.844238 (!).
   So our example 2 GB drive would have 261 cylinders, 63 sectors per
   track and 255 heads.

   If you are not sure about this, or FreeBSD fails to detect the
   geometry correctly during installation, the simplest way around
   this is usually to create a small DOS partition on the disk. The
   BIOS should then detect the correct geometry, and you can always
   remove the DOS partition in the partition editor if you do not
   want to keep it. You might want to leave it around for programming
   network cards and the like, however.

   Alternatively, there is a freely available utility distributed
   with FreeBSD called pfdisk.exe. You can find it in the tools
   subdirectory on the FreeBSD CD-ROM or on the various FreeBSD FTP
   sites. This program can be used to work out what geometry the
   other operating systems on the disk are using. You can then enter
   this geometry in the partition editor.

   3.15. Are there any restrictions on how I divide the disk up?

   Yes. You must make sure that your root partition is below 1024
   cylinders so the BIOS can boot the kernel from it. (Note that this
   is a limitation in the PC's BIOS, not FreeBSD).

   For a SCSI drive, this will normally imply that the root partition
   will be in the first 1024 MB (or in the first 4096 MB if extended
   translation is turned on -- see previous question). For IDE, the
   corresponding figure is 504 MB.

   3.16. Is FreeBSD compatible with any disk managers?

   FreeBSD recognizes the Ontrack Disk Manager and makes allowances
   for it. Other disk managers are not supported.

   If you just want to use the disk with FreeBSD you do not need a
   disk manager. Just configure the disk for as much space as the
   BIOS can deal with (usually 504 megabytes), and FreeBSD should
   figure out how much space you really have. If you are using an old
   disk with an MFM controller, you may need to explicitly tell
   FreeBSD how many cylinders to use.

   If you want to use the disk with FreeBSD and another operating
   system, you may be able to do without a disk manager: just make
   sure the FreeBSD boot partition and the slice for the other
   operating system are in the first 1024 cylinders. If you are
   reasonably careful, a 20 megabyte boot partition should be plenty.

   3.17. When I boot FreeBSD for the first time after install I get
   "Missing Operating System". What is happening?

   This is classically a case of FreeBSD and DOS or some other OS
   conflicting over their ideas of disk geometry. You will have to
   reinstall FreeBSD, but obeying the instructions given above will
   almost always get you going.

   3.18. Why can I not get past the boot manager's F? prompt?

   This is another symptom of the problem described in the preceding
   question. Your BIOS geometry and FreeBSD geometry settings do not
   agree! If your controller or BIOS supports cylinder translation
   (often marked as ">1GB drive support"), try toggling its setting
   and reinstalling FreeBSD.

   3.19. Do I need to install the complete sources?

   In general, no. However, we would strongly recommend that you
   install, at a minimum, the base source kit, which includes several
   of the files mentioned here, and the sys (kernel) source kit,
   which includes sources for the kernel. There is nothing in the
   system which requires the presence of the sources to operate,
   however, except for the kernel-configuration program config(8).
   With the exception of the kernel sources, our build structure is
   set up so that you can read-only mount the sources from elsewhere
   via NFS and still be able to make new binaries (due to the
   kernel-source restriction, we recommend that you not mount this on
   /usr/src directly, but rather in some other location with
   appropriate symbolic links to duplicate the top-level structure of
   the source tree).

   Having the sources on-line and knowing how to build a system with
   them will make it much easier for you to upgrade to future
   releases of FreeBSD.

   To actually select a subset of the sources, use the Custom menu
   item when you are in the Distributions menu of the system
   installation tool.

   3.20. Do I need to build a kernel?

   Building a new kernel was originally pretty much a required step
   in a FreeBSD installation, but more recent releases have benefited
   from the introduction of much friendlier kernel configuration
   methods. It is very easy to configure the kernel's configuration
   by much more flexible "hints" which can be set at the loader
   prompt.

   It may still be worthwhile building a new kernel containing just
   the drivers that you need, just to save a bit of RAM, but it is no
   longer necessary for most systems.

   3.21. Should I use DES, Blowfish, or MD5 passwords and how do I
   specify which form my users receive?

   The default password format on FreeBSD is to use MD5-based
   passwords. These are believed to be more secure than the
   traditional UNIX password format, which used a scheme based on the
   DES algorithm. DES passwords are still available if you need to
   share your password file with legacy operating systems which still
   use the less secure password format. FreeBSD also allows you to
   use the Blowfish password format, which is more secure. Which
   password format to use for new passwords is controlled by the
   passwd_format login capability in /etc/login.conf, which takes
   values of des, blf (if these are available) or md5. See the
   login.conf(5) manual page for more information about login
   capabilities.

   3.22. Why does the boot floppy start, but hang at the Probing
   Devices... screen?

   If you have a IDE Zip(R) or Jaz(R) drive installed, remove it and
   try again. The boot floppy can get confused by the drives. After
   the system is installed you can reconnect the drive. Hopefully
   this will be fixed in a later release.

   3.23. Why do I get a "panic: can't mount root" error when
   rebooting the system after installation?

   This error comes from confusion between the boot block's and the
   kernel's understanding of the disk devices. The error usually
   manifests on two-disk IDE systems, with the hard disks arranged as
   the master or single device on separate IDE controllers, with
   FreeBSD installed on the secondary IDE controller. The boot blocks
   think the system is installed on ad0 (the second BIOS disk) while
   the kernel assigns the first disk on the secondary controller
   device, ad2. After the device probing, the kernel tries to mount
   what the boot blocks think is the boot disk, ad0, while it is
   really ad2, and fails.

   To fix the problem, do one of the following:

    1. Reboot the system and hit Enter at the Booting kernel in 10
       seconds; hit [Enter] to interrupt prompt. This will drop you
       into the boot loader.

       Then type set root_disk_unit="disk_number". disk_number will
       be 0 if FreeBSD is installed on the master drive on the first
       IDE controller, 1 if it is installed on the slave on the first
       IDE controller, 2 if it is installed on the master of the
       second IDE controller, and 3 if it is installed on the slave
       of the second IDE controller.

       Then type boot, and your system should boot correctly.

       To make this change permanent (i.e, so you do not have to do
       this every time you reboot or turn on your FreeBSD machine),
       put the line root_disk_unit="disk_number" in
       /boot/loader.conf.local.

    2. Move the FreeBSD disk onto the primary IDE controller, so the
       hard disks are consecutive.

   3.24. What are the limits for memory?

   Memory limits depend on the platform used. On a standard i386
   install, the limit is 4 GB but more memory can be supported
   through pae(4). See instructions for using 4 GB or more memory on
   i386.

   FreeBSD/pc98 has a limit of 4 GB memory, and PAE can not be used
   with it. Other architectures supported by FreeBSD have much higher
   theoretical limits on maximum memory (many terabytes).

   3.25. What are the limits for FFS file systems?

   For FFS file systems, the maximum theoretical limit is 8 TB (2 G
   blocks), or 16 TB for the default block size of 8 KB. In practice,
   there is a soft limit of 1 TB, but with modifications file systems
   with 4 TB are possible (and exist).

   The maximum size of a single FFS file is approximately 1 G blocks,
   or 4 TB with a block size of 4 KB.

   Table 3-1. Maximum File Sizes

   +-----------------------------------------+
   | FS Block Size |   Works   | Should Work |
   |---------------+-----------+-------------|
   | 4 KB          | > 4 GB    | 4 TB - 1    |
   |---------------+-----------+-------------|
   | 8 KB          | > 32 GB   | 32 TB - 1   |
   |---------------+-----------+-------------|
   | 16 KB         | > 128 GB  | 32 TB - 1   |
   |---------------+-----------+-------------|
   | 32 KB         | > 512 GB  | 64 TB - 1   |
   |---------------+-----------+-------------|
   | 64 KB         | > 2048 GB | 128 TB - 1  |
   +-----------------------------------------+

   When the FS block size is 4 KB, triple indirect blocks work and
   everything should be limited by the maximum FS block number that
   can be represented using triple indirect blocks (approx.
   10243 + 10242 + 1024), but everything is limited by a (wrong)
   limit of 1 G - 1 on FS block numbers. The limit on FS block
   numbers should be 2 G - 1. There are some bugs for FS block
   numbers near 2 G - 1, but such block numbers are unreachable when
   the FS block size is 4 KB.

   For block sizes of 8 KB and larger, everything should be limited
   by the 2 G - 1 limit on FS block numbers, but is actually limited
   by the 1 G - 1 limit on FS block numbers. Using the correct limit
   of 2 G - 1 blocks does cause problems.

   3.26. Why do I get an error message, "archsw.readin.failed" after
   compiling and booting a new kernel?

   Because your world and kernel are out of sync. This is not
   supported. Be sure you use make buildworld and make buildkernel to
   update your kernel.

   You can boot by specifying the kernel directly at the second
   stage, pressing any key when the | shows up before loader is
   started.

   3.27. Installation crashes while booting, what can I do?

   Try disabling ACPI support. When the bootloader loads, press the
   Space key. The system will display the following:

 OK

   Type:

 unset acpi_load

   And then type:

 boot

     --------------------------------------------------------------

                    Chapter 4 Hardware Compatibility

4.1 General

   4.1.1. I want to get a piece of hardware for my FreeBSD system.
   Which model/brand/type is best?

   4.1.1. I want to get a piece of hardware for my FreeBSD system.
   Which model/brand/type is best?

   This is discussed continually on the FreeBSD mailing lists. Since
   hardware changes so quickly, however, we expect this. We still
   strongly recommend that you read through the Hardware Notes for
   FreeBSD 8.0 or 7.2 and search the mailing list archives before
   asking about the latest and greatest hardware. Chances are a
   discussion about the type of hardware you are looking for took
   place just last week.

   If you are looking for a laptop, check the FreeBSD laptop computer
   mailing list archives. Otherwise, you probably want the archives
   for the FreeBSD general questions mailing list, or possibly a
   specific mailing list for a particular hardware type.

     --------------------------------------------------------------

4.2 Memory

   4.2.1. Does FreeBSD support more than 4 GB of memory (RAM)? More
   than 16 GB? More than 48 GB?

   4.2.2. Why does FreeBSD report less than 4 GB memory when
   installed on an i386 machine?

   4.2.1. Does FreeBSD support more than 4 GB of memory (RAM)? More
   than 16 GB? More than 48 GB?

   Yes. FreeBSD as an operating system generally supports as much
   physical memory (RAM) as the platform it is running on does. Keep
   in mind that different platforms have different limits for memory;
   for example i386 without PAE supports at most 4 GB of memory (and
   usually less than that because of PCI address space) and i386 with
   PAE supports at most 64 GB memory. AMD64 platforms currently
   deployed support up to 1 TB of physical memory.

   4.2.2. Why does FreeBSD report less than 4 GB memory when
   installed on an i386 machine?

   The total address space on i386 machines is 32-bit, meaning that
   at most 4 GB of memory is addressable (can be accessed).
   Furthermore, some addresses in this range are reserved by hardware
   for different purposes, for example for using and controlling PCI
   devices, for accessing video memory, and so on. Therefore, the
   total amount of memory usable by the operating system for its
   kernel and applications is limited to significantly less than
   4 GB. Usually, 3.2 GB to 3.7 GB is the maximum usable physical
   memory in this configuration.

   To access more than 3.2 GB to 3.7 GB of installed memory (meaning
   up to 4 GB but also more than 4 GB), a special tweak called PAE
   must be used. PAE stands for Physical Address Extension and is a
   way for 32-bit x86 CPUs to address more than 4 GB of memory. It
   remaps the memory that would otherwise be overlayed by address
   reservations for hardware devices above the 4 GB range and uses it
   as additional physical memory (see pae(4)). Using PAE has some
   drawbacks; this mode of memory access is a little bit slower than
   the normal (without PAE) mode and loadable modules (see kld(4))
   are not supported. This means all drivers must be compiled into
   the kernel.

   The most common way to enable PAE is to build a new kernel with
   the special ready-provided kernel configuration file called PAE,
   which is already configured to build a safe kernel. Note that some
   entries in this kernel configuration file are too conservative and
   some drivers marked as unready to be used with PAE are actually
   usable. A rule of thumb is that if the driver is usable on 64-bit
   architectures (like AMD64), it is also usable with PAE. If you
   wish to create your own kernel configuration file, you can enable
   PAE by adding the following line to your configuration:

 options       PAE

   PAE is not much used nowadays because most new x86 hardware also
   supports running in 64-bit mode, known as AMD64 or Intel 64. It
   has a much larger address space and does not need such tweaks.
   FreeBSD supports AMD64 and it is recommended that this version of
   FreeBSD be used instead of the i386 version if 4 GB or more memory
   is required.

     --------------------------------------------------------------

4.3 Architectures and Processors

   4.3.1. Does FreeBSD support architectures other than the x86?

   4.3.2. Does FreeBSD support Symmetric Multiprocessing (SMP)?

   4.3.1. Does FreeBSD support architectures other than the x86?

   Yes. FreeBSD currently runs on the Intel x86 and the AMD64
   architectures. The Intel EM64T, IA-64, ARM, PowerPC, sun4v and
   Sparc64(R) architectures are also supported. Upcoming platforms
   are MIPS(R) and S/390(R), join the FreeBSD MIPS porting mailing
   list for more information about ongoing work on the MIPS platform.
   For general discussion on new architectures, join the FreeBSD
   non-Intel platforms porting mailing list.

   If your machine has a different architecture and you need
   something right now, we suggest you look at NetBSD or OpenBSD.

   4.3.2. Does FreeBSD support Symmetric Multiprocessing (SMP)?

   Symmetric multi-processor (SMP) systems are generally supported by
   FreeBSD, although in some cases, BIOS or motherboard bugs may
   generate some problems. Perusing the FreeBSD symmetric
   multiprocessing mailing list may yield some clues.

   FreeBSD will take advantage of HyperThreading (HTT) support on
   Intel CPUs that support this feature. A kernel with the options
   SMP feature enabled will automatically detect the additional
   logical processors. The default FreeBSD scheduler treats the
   logical processors the same as additional physical processors; in
   other words, no attempt is made to optimize scheduling decisions
   given the shared resources between logical processors within the
   same CPU. Because this naive scheduling can result in suboptimal
   performance, under certain circumstances it may be useful to
   disable the logical processors with the machdep.hlt_logical_cpus
   sysctl variable. It is also possible to halt any CPU in the idle
   loop with the machdep.hlt_cpus sysctl variable. The smp(4) manual
   page has more details.

     --------------------------------------------------------------

4.4 Hard Drives, Tape Drives, and CD and DVD Drives

   4.4.1. What kind of hard drives does FreeBSD support?

   4.4.2. Which SCSI or SAS controllers are supported?

   4.4.3. What types of tape drives are supported?

   4.4.4. Does FreeBSD support tape changers?

   4.4.5. Which CD-ROM drives are supported by FreeBSD?

   4.4.6. Which CD-RW drives are supported by FreeBSD?

   4.4.7. Does FreeBSD support Zip drives?

   4.4.8. Does FreeBSD support Jaz, EZ and other removable drives?

   4.4.1. What kind of hard drives does FreeBSD support?

   FreeBSD supports EIDE, SATA, SCSI, and SAS drives (with a
   compatible controller; see the next section), and all drives using
   the original "Western Digital" interface (MFM, RLL, ESDI, and of
   course IDE). A few ESDI controllers that use proprietary
   interfaces may not work: stick to WD1002/3/6/7 interfaces and
   clones.

   4.4.2. Which SCSI or SAS controllers are supported?

   See the complete list in the Hardware Notes for FreeBSD 8.0 or
   7.2.

   4.4.3. What types of tape drives are supported?

   FreeBSD supports SCSI and QIC-36 (with a QIC-02 interface). This
   includes 8-mm (aka Exabyte) and DAT drives.

   Some of the early 8-mm drives are not quite compatible with
   SCSI-2, and may not work well with FreeBSD.

   4.4.4. Does FreeBSD support tape changers?

   FreeBSD supports SCSI changers using the ch(4) device and the
   chio(1) command. The details of how you actually control the
   changer can be found in the chio(1) manual page.

   If you are not using AMANDA or some other product that already
   understands changers, remember that they only know how to move a
   tape from one point to another, so you need to keep track of which
   slot a tape is in, and which slot the tape currently in the drive
   needs to go back to.

   4.4.5. Which CD-ROM drives are supported by FreeBSD?

   Any SCSI drive connected to a supported controller is supported.

   The following proprietary CD-ROM interfaces are also supported:

     * Mitsumi LU002 (8-bit), LU005 (16-bit) and FX001D (16-bit 2x
       Speed).

     * Sony CDU 31/33A

     * Sound Blaster Non-SCSI CD-ROM

     * Matsushita/Panasonic CD-ROM

     * ATAPI compatible IDE CD-ROMs

   All non-SCSI cards are known to be extremely slow compared to SCSI
   drives, and some ATAPI CD-ROMs may not work.

   The official FreeBSD CD-ROM ISO, and CD-ROMs from Daemon News and
   FreeBSD Mall, support booting directly from the CD.

   4.4.6. Which CD-RW drives are supported by FreeBSD?

   FreeBSD supports any ATAPI-compatible IDE CD-R or CD-RW drive. See
   burncd(8) for details.

   FreeBSD also supports any SCSI CD-R or CD-RW drives. Install and
   use the cdrecord command from the ports or packages system, and
   make sure that you have the pass device compiled in your kernel.

   4.4.7. Does FreeBSD support Zip drives?

   FreeBSD supports SCSI and ATAPI (IDE) Zip drives out of the box.
   SCSI ZIP drives can only be set to run at SCSI target IDs 5 or 6,
   but if your SCSI host adapter's BIOS supports it you can even boot
   from it. It is not clear which host adapters support booting from
   targets other than 0 or 1, so you will have to consult your
   adapter's documentation if you would like to use this feature.

   FreeBSD also supports Parallel Port Zip Drives. Check that your
   kernel contains the scbus0, da0, ppbus0, and vp0 drivers (the
   GENERIC kernel contains everything except vp0). With all these
   drivers present, the Parallel Port drive should be available as
   /dev/da0s4. Disks can be mounted using mount /dev/da0s4 /mnt OR
   (for DOS disks) mount -t msdosfs /dev/da0s4 /mnt as appropriate.

   Also check out the FAQ on removable drives later in this chapter,
   and the note on "formatting"in the Administration chapter.

   4.4.8. Does FreeBSD support Jaz, EZ and other removable drives?

   They work. Most of these are SCSI devices, so they look like SCSI
   disks to FreeBSD. The IDE EZ looks like an IDE drive.

   Make sure that any external units are powered on when booting the
   system.

   To change the media while running, check out mount(8), umount(8),
   and camcontrol(8) (for SCSI devices) or atacontrol(8) (for IDE
   devices), plus the discussion on using removable drives later in
   the FAQ.

     --------------------------------------------------------------

4.5 Keyboards and Mice

   4.5.1. Does FreeBSD support my USB keyboard?

   4.5.2. I have an unusual bus mouse. How do I set it up?

   4.5.3. How do I use my PS/2 ("mouse port" or "keyboard") mouse?

   4.5.4. Is it possible to use a mouse in any way outside the X
   Window system?

   4.5.5. How do I cut and paste text with a mouse in the text
   console?

   4.5.6. My mouse has a fancy wheel and buttons. Can I use them in
   FreeBSD?

   4.5.7. How do I use the mouse/trackball/touchpad on my laptop?

   4.5.8. How do I use my delete key in sh and csh?

   4.5.1. Does FreeBSD support my USB keyboard?

   FreeBSD supports USB keyboards out-of-the-box. Once you have USB
   keyboard support enabled on your system, the AT keyboard becomes
   /dev/kbd0 and the USB keyboard becomes /dev/kbd1, if both are
   connected to the system. If there is the USB keyboard only, it
   will be /dev/ukbd0.

   If you want to use the USB keyboard in the console, you have to
   explicitly tell the console driver to use the existing USB
   keyboard. This can be done by running the following command as a
   part of system initialization.

 # kbdcontrol -k /dev/kbd1 < /dev/console > /dev/null

   Note that if the USB keyboard is the only keyboard, it is accessed
   as /dev/ukbd0, thus, the command should look like:

 # kbdcontrol -k /dev/ukbd0 < /dev/console > /dev/null

     Note: To make this change permanent across reboots, add
     keyboard="/dev/ukbd0" to /etc/rc.conf.

   Once this is done, the USB keyboard should work in the X
   environment as well without any special settings.

   If you want to switch back to the default keyboard, use this
   command:

 # kbdcontrol -k /dev/kbd0 > /dev/null

   To allow using both the second USB keyboard and the first AT
   keyboard at the same time on a console via kbdmux(4) driver type
   the following commands:

 # kbdcontrol -K < /dev/console > /dev/null
 # kbdcontrol -a atkbd0 < /dev/kbdmux0 > /dev/null
 # kbdcontrol -a ukbd1 < /dev/kbdmux0 > /dev/null
 # kbdcontrol -k /dev/kbdmux0 < /dev/console > /dev/null

   See the ukbd(4), kbdcontrol(1) and kbdmux(4) manual pages for more
   information.

     Note: Hot-plugging and unplugging of the USB keyboard may not
     work quite right yet. We recommend connecting the keyboard
     before starting the system and leaving it connected until the
     system is shutdown to avoid issues.

   4.5.2. I have an unusual bus mouse. How do I set it up?

   FreeBSD supports the bus mouse and the InPort bus mouse from such
   manufacturers as Microsoft, Logitech and ATI. The GENERIC kernel
   does not include the device driver. To build a custom kernel with
   the bus mouse driver, add the following line to the kernel config
   file:

 device mse0 at isa? port 0x23c irq5

   Bus mice usually come with dedicated interface cards. These cards
   may allow you to set the port address and the IRQ number other
   than shown above. Refer to the manual of your mouse and the mse(4)
   manual page for more information.

   4.5.3. How do I use my PS/2 ("mouse port" or "keyboard") mouse?

   The PS/2 mouse is supported out-of-the-box. The necessary device
   driver, psm, is included in the kernel.

   If your custom kernel does not have this, add the following line
   to your kernel configuration and compile a new kernel.

 device psm0 at atkbdc? irq 12

   Once the kernel detects psm0 correctly at boot time, a device node
   psm0 will be created automatically.

   4.5.4. Is it possible to use a mouse in any way outside the X
   Window system?

   If you are using the default console driver, syscons(4), you can
   use a mouse pointer in text consoles to cut & paste text. Run the
   mouse daemon, moused(8), and turn on the mouse pointer in the
   virtual console:

 # moused -p /dev/xxxx -t yyyy
 # vidcontrol -m on

   Where xxxx is the mouse device name and yyyy is a protocol type
   for the mouse. The mouse daemon can automatically determine the
   protocol type of most mice, except old serial mice. Specify the
   auto protocol to invoke automatic detection. If automatic
   detection does not work, see the moused(8) manual page for a list
   of supported protocol types.

   If you have a PS/2 mouse, just add moused_enable="YES" to
   /etc/rc.conf to start the mouse daemon at boot-time. Additionally,
   if you would like to use the mouse daemon on all virtual terminals
   instead of just the console, add allscreens_flags="-m on" to
   /etc/rc.conf.

   When the mouse daemon is running, access to the mouse must be
   coordinated between the mouse daemon and other programs such as X
   Windows. Refer to the FAQ Why does my mouse not work with X? for
   more details on this issue.

   4.5.5. How do I cut and paste text with a mouse in the text
   console?

   Once you get the mouse daemon running (see the previous section),
   hold down the button 1 (left button) and move the mouse to select
   a region of text. Then, press the button 2 (middle button) to
   paste it at the text cursor. Pressing button 3 (right button) will
   "extend" the selected region of text.

   If your mouse does not have a middle button, you may wish to
   emulate one or remap buttons using mouse daemon options. See the
   moused(8) manual page for details.

   4.5.6. My mouse has a fancy wheel and buttons. Can I use them in
   FreeBSD?

   The answer is, unfortunately, "It depends". These mice with
   additional features require specialized driver in most cases.
   Unless the mouse device driver or the user program has specific
   support for the mouse, it will act just like a standard two, or
   three button mouse.

   For the possible usage of wheels in the X Window environment,
   refer to that section.

   4.5.7. How do I use the mouse/trackball/touchpad on my laptop?

   Please refer to the answer to the previous question.

   4.5.8. How do I use my delete key in sh and csh?

   For the Bourne Shell, add the following lines to your .shrc. See
   sh(1) and editrc(5).

 bind ^? ed-delete-next-char # for console
 bind ^[[3~ ed-delete-next-char # for xterm

   For the C Shell, add the following lines to your .cshrc. See
   csh(1).

 bindkey ^? delete-char # for console
 bindkey ^[[3~ delete-char # for xterm

   For more information, see this page.

     --------------------------------------------------------------

4.6 Networking and Serial Devices

   4.6.1. Which network cards does FreeBSD support?

   4.6.2. Does FreeBSD support software modems, such as Winmodems?

   4.6.3. Is there a native driver for the Broadcom 43xx cards?

   4.6.4. Which multi-port serial cards are supported by FreeBSD?

   4.6.5. How do I get the boot: prompt to show on the serial
   console?

   4.6.1. Which network cards does FreeBSD support?

   See the Hardware Notes supplied with each release of FreeBSD for a
   more complete list.

   4.6.2. Does FreeBSD support software modems, such as Winmodems?

   FreeBSD supports many software modems via add-on software. For
   example, the comms/ltmdm port adds support for modems based on the
   very popular Lucent LT chipsets.

   You cannot install FreeBSD via a software modem; this software
   must be installed after the OS is installed.

   4.6.3. Is there a native driver for the Broadcom 43xx cards?

   No, and there is not likely to be.

   Broadcom refuses to publically release programming information for
   their wireless chipsets, most likely because they use software
   controlled radios. In order to get FCC type acceptance for their
   parts, they have to ensure that users cannot arbitrarily set
   things like operating frequencies, modulation parameters and power
   output. But without knowing how to program the chipsets, it is
   nearly impossible to write a driver.

   4.6.4. Which multi-port serial cards are supported by FreeBSD?

   There is a list of these in the Serial Communications chapter of
   the handbook.

   Some unnamed clone cards have also been known to work, especially
   those that claim to be AST compatible.

   Check the sio(4) manual page to get more information on
   configuring such cards.

   4.6.5. How do I get the boot: prompt to show on the serial
   console?

   See this section of the handbook.

     --------------------------------------------------------------

4.7 Sound Devices

   4.7.1. Which sound cards are supported by FreeBSD?

   4.7.2. Workarounds for no sound from my pcm(4) sound card?

   4.7.1. Which sound cards are supported by FreeBSD?

   FreeBSD supports various sound cards (for more details, see
   FreeBSD Release Information and the snd(4) manual page). There is
   also limited support for MPU-401 and compatible MIDI cards. Cards
   conforming to the Microsoft(R) Sound System specification are also
   supported.

     Note: This is only for sound! This driver does not support
     CD-ROMs, SCSI or joysticks on these cards, except for the
     SoundBlaster(R). The SoundBlaster SCSI interface and some
     non-SCSI CD-ROMs are supported, but you cannot boot off this
     device.

   4.7.2. Workarounds for no sound from my pcm(4) sound card?

   Some sound cards set their output volume to 0 at every boot. Run
   the following command every time the machine boots:

 # mixer pcm 100 vol 100 cd 100

     --------------------------------------------------------------

4.8 Other Hardware

   4.8.1. Does FreeBSD support power management on my laptop?

   4.8.2. How do I disable ACPI?

   4.8.3. Why does my Micron system hang at boot time?

   4.8.4. The boot floppy hangs on a system with an ASUS K7V
   motherboard. How do I fix this?

   4.8.5. Why does my 3Com(R) PCI network card not work with my
   Micron computer?

   4.8.1. Does FreeBSD support power management on my laptop?

   FreeBSD supports APM on certain machines. Further information can
   be found in apm(4).

   FreeBSD also supports the ACPI features found in most modern
   hardware. Further information can be found in acpi(4). If a system
   supports both APM and ACPI, either can be used. We suggest you try
   both and choose the one that best fits your needs.

   4.8.2. How do I disable ACPI?

   Add following line

 hint.acpi.0.disabled="1"

   into your /boot/device.hints file.

   4.8.3. Why does my Micron system hang at boot time?

   Certain Micron motherboards have a non-conforming PCI BIOS
   implementation that causes grief when FreeBSD boots because PCI
   devices do not get configured at their reported addresses.

   Disable the "Plug and Play Operating System" flag in the BIOS to
   work around this problem.

   4.8.4. The boot floppy hangs on a system with an ASUS K7V
   motherboard. How do I fix this?

   Go into the BIOS setup and disable the "boot virus protection".

   4.8.5. Why does my 3Com(R) PCI network card not work with my
   Micron computer?

   See the previous answer.

     --------------------------------------------------------------

                       Chapter 5 Troubleshooting

   5.1. Why is FreeBSD finding the wrong amount of memory on i386
   hardware?

   5.2. What do I do when I have bad blocks on my hard drive?

   5.3. Why does FreeBSD not detect my HP Netserver's SCSI
   controller?

   5.4. I keep seeing messages like "ed1: timeout". What do these
   messages mean?

   5.5. Why did my 3Com 3C509 card stop working for no apparent
   reason?

   5.6. My parallel printer is ridiculously slow. What can I do?

   5.7. Why do my programs occasionally die with "Signal 11" errors?

   5.8. My system crashes with either "Fatal trap 12: page fault in
   kernel mode", or "panic:", and spits out a bunch of information.
   What should I do?

   5.9. Why does the screen go black and lose sync when I boot?

   5.10. Why does FreeBSD only use 64 MB of RAM when my system has
   128 MB of RAM installed?

   5.11. My system has more than 1 GB of RAM, and I'm getting panics
   with "kmem_map too small" messages. What is wrong?

   5.12. My system does not have 1 GB of RAM, and FreeBSD still
   panics with "kmem_map too small"!

   5.13. Why do I get the error "kernel: proc: table is full"?

   5.14. Why do I get an error reading "CMAP busy" when rebooting
   with a new kernel?

   5.15. What does the message "ahc0: brkadrint, Illegal Host Access
   at seqaddr 0x0" mean?

   5.16. When I boot my system, I get the error "ahc0: illegal cable
   configuration". My cabling is correct. What is going on?

   5.17. Why does sendmail give me an error reading "mail loops back
   to myself"?

   5.18. Why do full screen applications on remote machines
   misbehave?

   5.19. Why is my PnP card not found (or found as unknown)?

   5.20. Why do I get the error "nlist failed" when running, for
   example, top or systat?

   5.21. Why does it take so long to connect to my computer via ssh
   or telnet?

   5.22. What does "stray IRQ" mean?

   5.23. Why does "file: table is full" show up repeatedly in
   dmesg(8)?

   5.24. Why are "calcru: negative runtime" or "calcru: runtime went
   backwards" messages pounding the console?

   5.25. Why does the clock on my computer keep incorrect time?

   5.26. Why did my laptop fail to correctly probe PC cards?

   5.27. Why does FreeBSD's boot loader display "Read error" and stop
   after the BIOS screen?

   5.28. Another operating system destroyed my Boot Manager. How do I
   get it back?

   5.29. What does the error "swap_pager: indefinite wait buffer:"
   mean?

   5.30. What are "UDMA ICRC" errors, and how do I fix them?

   5.31. What is a "lock order reversal"?

   5.32. What does "Called ... with the following non-sleepable locks
   held" mean?

   5.33. Why does buildworld/installworld die with the message
   "touch: not found"?

   5.1. Why is FreeBSD finding the wrong amount of memory on i386
   hardware?

   The most likely reason is the difference between physical memory
   addresses and virtual addresses.

   The convention for most PC hardware is to use the memory area
   between 3.5 GB and 4 GB for a special purpose (usually for PCI).
   This address space is used to access PCI hardware. As a result
   real, physical memory can not be accessed by that address space.

   What happens to the memory that should appear in that location is
   dependent on your hardware. Unfortunately, some hardware does
   nothing and the ability to use that last 500 MB of RAM is entirely
   lost.

   Luckily, most hardware remaps the memory to a higher location so
   that it can still be used. However, this can cause some confusion
   if you watch the boot messages.

   On a 32-bit version of FreeBSD, the memory appears lost, since it
   will be remapped above 4 GB, which a 32-bit kernel is unable to
   access. In this case, the solution is to build a PAE enabled
   kernel. See the entry on memory limits and about different memory
   limits on different platforms for more information.

   On a 64-bit version of FreeBSD, or when running a PAE-enabled
   kernel, FreeBSD will correctly detect and remap the memory so it
   is usable. During boot, however, it may seem as if FreeBSD is
   detecting more memory than the system really has, due to the
   described remapping. This is normal and the available memory will
   be corrected as the boot process completes.

   5.2. What do I do when I have bad blocks on my hard drive?

   With SCSI drives, the drive should be capable of re-mapping these
   automatically. However, many drives ship with this feature
   disabled.

   To enable bad block remapping edit the first device page mode,
   which can be done by giving the command (as root)

 # camcontrol modepage sd0 -m 1 -e -P 3

   and changing the values of AWRE and ARRE from 0 to 1:

 AWRE (Auto Write Reallocation Enbld):  1
 ARRE (Auto Read Reallocation Enbld):  1

   Modern IDE drives also have bad block remapping features in the
   controller, and they ship with this feature turned on.

   If you see warnings about bad blocks (on either type of drive), it
   is time to consider replacing the drive. You might be able to use
   the drive manufacturer's diagnostic program to lock out those bad
   blocks, but at best this will buy you some time.

   5.3. Why does FreeBSD not detect my HP Netserver's SCSI
   controller?

   This is basically a known problem. The EISA on-board SCSI
   controller in the HP Netserver machines occupies EISA slot number
   11, so all the "true" EISA slots are in front of it. Alas, the
   address space for EISA slots >= 10 collides with the address space
   assigned to PCI, and FreeBSD's auto-configuration currently cannot
   handle this situation very well.

   So now, the best you can do is to pretend there is no address
   range clash :), by bumping the kernel option EISA_SLOTS to a value
   of 12. Configure and compile a kernel, as described in the
   Handbook entry on configuring the kernel.

   Of course, this does present you with a chicken-and-egg problem
   when installing on such a machine. In order to work around this
   problem, a special hack is available inside UserConfig. Do not use
   the "visual" interface, but the plain command-line interface
   there. Simply type the following command at the prompt and install
   your system as usual:

 eisa 12
 quit

   While it is recommended you compile and install a custom kernel
   anyway.

   Hopefully, future versions will have a proper fix for this
   problem.

     Note: You cannot use a dangerously dedicated disk with an HP
     Netserver. See this note for more info.

   5.4. I keep seeing messages like "ed1: timeout". What do these
   messages mean?

   This is usually caused by an interrupt conflict (e.g., two boards
   using the same IRQ). Boot with the -c option and change the
   ed0/de0/... entry to match your board.

   If you are using the BNC connector on your network card, you may
   also see device timeouts because of bad termination. To check
   this, attach a terminator directly to the NIC (with no cable) and
   see if the error messages go away.

   Some NE2000 compatible cards will give this error if there is no
   link on the UTP port or if the cable is disconnected.

   5.5. Why did my 3Com 3C509 card stop working for no apparent
   reason?

   This card has a bad habit of losing its configuration information.
   Refresh your card's settings with the DOS utility 3c5x9.exe.

   5.6. My parallel printer is ridiculously slow. What can I do?

   If the only problem is that the printer is terribly slow, try
   changing your printer port mode as discussed in the Printer Setup
   section of the Handbook.

   5.7. Why do my programs occasionally die with "Signal 11" errors?

   Signal 11 errors are caused when your process has attempted to
   access memory which the operating system has not granted it access
   to. If something like this is happening at seemingly random
   intervals then you need to start investigating things very
   carefully.

   These problems can usually be attributed to either:

    1. If the problem is occurring only in a specific application
       that you are developing yourself it is probably a bug in your
       code.

    2. If it is a problem with part of the base FreeBSD system, it
       may also be buggy code, but more often than not these problems
       are found and fixed long before us general FAQ readers get to
       use these bits of code (that is what -current is for).

   In particular, a dead giveaway that this is not a FreeBSD bug is
   if you see the problem when you are compiling a program, but the
   activity that the compiler is carrying out changes each time.

   For example, suppose you are running make buildworld, and the
   compile fails while trying to compile ls.c into ls.o. If you then
   run make buildworld again, and the compile fails in the same place
   then this is a broken build -- try updating your sources and try
   again. If the compile fails elsewhere then this is almost
   certainly hardware.

   What you should do:

   In the first case you can use a debugger e.g. gdb(1) to find the
   point in the program which is attempting to access a bogus address
   and then fix it.

   In the second case you need to verify that it is not your hardware
   at fault.

   Common causes of this include:

    1. Your hard disks might be overheating: Check the fans in your
       case are still working, as your disk (and perhaps other
       hardware might be overheating).

    2. The processor running is overheating: This might be because
       the processor has been overclocked, or the fan on the
       processor might have died. In either case you need to ensure
       that you have hardware running at what it is specified to run
       at, at least while trying to solve this problem. i.e. Clock it
       back to the default settings.

       If you are overclocking then note that it is far cheaper to
       have a slow system than a fried system that needs replacing!
       Also the wider community is not often sympathetic to problems
       on overclocked systems, whether you believe it is safe or not.

    3. Dodgy memory: If you have multiple memory SIMMS/DIMMS
       installed then pull them all out and try running the machine
       with each SIMM or DIMM individually and narrow the problem
       down to either the problematic DIMM/SIMM or perhaps even a
       combination.

    4. Over-optimistic Motherboard settings: In your BIOS settings,
       and some motherboard jumpers you have options to set various
       timings, mostly the defaults will be sufficient, but
       sometimes, setting the wait states on RAM too low, or setting
       the "RAM Speed: Turbo" option, or similar in the BIOS will
       cause strange behavior. A possible idea is to set to BIOS
       defaults, but it might be worth noting down your settings
       first!

    5. Unclean or insufficient power to the motherboard. If you have
       any unused I/O boards, hard disks, or CD-ROMs in your system,
       try temporarily removing them or disconnecting the power cable
       from them, to see if your power supply can manage a smaller
       load. Or try another power supply, preferably one with a
       little more power (for instance, if your current power supply
       is rated at 250 Watts try one rated at 300 Watts).

   You should also read the SIG11 FAQ (listed below) which has
   excellent explanations of all these problems, albeit from a
   Linux(R) viewpoint. It also discusses how memory testing software
   or hardware can still pass faulty memory.

   Finally, if none of this has helped it is possible that you have
   just found a bug in FreeBSD, and you should follow the
   instructions to send a problem report.

   There is an extensive FAQ on this at the SIG11 problem FAQ.

   5.8. My system crashes with either "Fatal trap 12: page fault in
   kernel mode", or "panic:", and spits out a bunch of information.
   What should I do?

   The FreeBSD developers are very interested in these errors, but
   need some more information than just the error you see. Copy your
   full crash message. Then consult the FAQ section on kernel panics,
   build a debugging kernel, and get a backtrace. This might sound
   difficult, but you do not need any programming skills; you just
   have to follow the instructions.

   5.9. Why does the screen go black and lose sync when I boot?

   This is a known problem with the ATI Mach64 video card. The
   problem is that this card uses address 2e8, and the fourth serial
   port does too. Due to a bug (feature?) in the sio(4) driver it
   will touch this port even if you do not have the fourth serial
   port, and even if you disable sio3 (the fourth port) which
   normally uses this address.

   Until the bug has been fixed, you can use this workaround:

    1. Enter -c at the boot prompt. (This will put the kernel into
       configuration mode).

    2. Disable sio0, sio1, sio2 and sio3 (all of them). This way the
       sio(4) driver does not get activated -- no problems.

    3. Type exit to continue booting.

   If you want to be able to use your serial ports, you will have to
   build a new kernel with the following modification: in
   /usr/src/sys/dev/sio/sio.c (or in /usr/src/sys/pc98/cbus/sio.c for
   pc98) find the one occurrence of the string 0x2e8 and remove that
   string and the preceding comma (keep the trailing comma). Now
   follow the normal procedure of building a new kernel.

   5.10. Why does FreeBSD only use 64 MB of RAM when my system has
   128 MB of RAM installed?

   Due to the manner in which FreeBSD gets the memory size from the
   BIOS, it can only detect 16 bits worth of Kbytes in size
   (65535 Kbytes = 64 MB) (or less... some BIOSes peg the memory size
   to 16 MB). If you have more than 64 MB, FreeBSD will attempt to
   detect it; however, the attempt may fail.

   To work around this problem, you need to use the kernel option
   specified below. There is a way to get complete memory information
   from the BIOS, but we do not have room in the bootblocks to do it.
   Someday when lack of room in the bootblocks is fixed, we will use
   the extended BIOS functions to get the full memory information...
   but for now we are stuck with the kernel option.

 options MAXMEM=n

   Where n is your memory in Kilobytes. For a 128 MB machine, you
   would want to use 131072.

   5.11. My system has more than 1 GB of RAM, and I'm getting panics
   with "kmem_map too small" messages. What is wrong?

   Normally, FreeBSD determines a number of kernel parameters, such
   as as the maximum number of files that can be open concurrently,
   from the amount of memory installed in the system. On systems with
   one gigabyte of RAM or more, this "auto sizing" mechanism may
   choose values that are too high: while starting up, the kernel
   allocates various tables and other structures that fill up most of
   the available kernel memory. Later on, while the system is
   running, the kernel has no more space left for dynamic memory
   allocations, and panics.

   Compile your own kernel, and add the VM_KMEM_SIZE_MAX to your
   kernel configuration file, increasing the maximum size to 400 MB
   (options VM_KMEM_SIZE_MAX=419430400). 400 MB appears to be
   sufficient for machines with up to 6 GB of memory.

   5.12. My system does not have 1 GB of RAM, and FreeBSD still
   panics with "kmem_map too small"!

   The panic indicates that the system ran out of virtual memory for
   network buffers (specifically, mbuf clusters). You can increase
   the amount of VM available for mbuf clusters by following the
   instructions in the Network Limits section of the Handbook.

   5.13. Why do I get the error "kernel: proc: table is full"?

   The FreeBSD kernel will only allow a certain number of processes
   to exist at one time. The number is based on the kern.maxusers
   sysctl(8) variable. kern.maxusers also affects various other
   in-kernel limits, such as network buffers (see this earlier
   question). If your machine is heavily loaded, you probably want to
   increase kern.maxusers. This will increase these other system
   limits in addition to the maximum number of processes.

   To adjust your kern.maxusers value, see the File/Process Limits
   section of the Handbook. (While that section refers to open files,
   the same limits apply to processes.)

   If your machine is lightly loaded, and you are simply running a
   very large number of processes, you can adjust this with the
   kern.maxproc tunable. If this tunable needs adjustment it needs to
   be defined in /boot/loader.conf. The tunable will not get adjusted
   until the system is rebooted. For more information about tuning
   tunables, you should see the loader.conf(5) and sysctl.conf(5)
   manual pages. If these processes are being run by a single user,
   you will also need to adjust kern.maxprocperuid to be one less
   than your new kern.maxproc value. (It must be at least one less
   because one system program, init(8), must always be running.)

   To make a sysctl change permanent place the proper value in
   /etc/sysctl.conf. More information about system tuning with
   sysctl(8) can be found at the Tuning with sysctl section of the
   Handbook.

   5.14. Why do I get an error reading "CMAP busy" when rebooting
   with a new kernel?

   The logic that attempts to detect an out of date /var/db/kvm_*.db
   files sometimes fails and using a mismatched file can sometimes
   lead to panics.

   If this happens, reboot single-user and do:

 # rm /var/db/kvm_*.db

   5.15. What does the message "ahc0: brkadrint, Illegal Host Access
   at seqaddr 0x0" mean?

   This is a conflict with an Ultrastor SCSI Host Adapter.

   During the boot process enter the kernel configuration menu and
   disable uha0, which is causing the problem.

   5.16. When I boot my system, I get the error "ahc0: illegal cable
   configuration". My cabling is correct. What is going on?

   Your motherboard lacks the external logic to support automatic
   termination. Switch your SCSI BIOS to specify the correct
   termination for your configuration rather than automatic
   termination. The ahc(4) driver cannot determine if the external
   logic for cable detection (and thus auto-termination) is
   available. The driver simply assumes that this support must exist
   if the configuration contained in the serial EEPROM is set to
   "automatic termination". Without the external cable detection
   logic the driver will often configure termination incorrectly,
   which can compromise the reliability of the SCSI bus.

   5.17. Why does sendmail give me an error reading "mail loops back
   to myself"?

   You can find a detailed answer for this question in the Handbook.

   5.18. Why do full screen applications on remote machines
   misbehave?

   The remote machine may be setting your terminal type to something
   other than the cons25 terminal type required by the FreeBSD
   console.

   There are a number of possible work-arounds for this problem:

     * After logging on to the remote machine, set your TERM shell
       variable to ansi or sco if the remote machine knows about
       these terminal types.

     * Use a VT100 emulator like screen at the FreeBSD console.
       screen offers you the ability to run multiple concurrent
       sessions from one terminal, and is a neat program in its own
       right. Each screen window behaves like a VT100 terminal, so
       the TERM variable at the remote end should be set to vt100.

     * Install the cons25 terminal database entry on the remote
       machine. The way to do this depends on the operating system on
       the remote machine. The system administration manuals for the
       remote system should be able to help you here.

     * Fire up an X server at the FreeBSD end and login to the remote
       machine using an X based terminal emulator such as xterm or
       rxvt. The TERM variable at the remote host should be set to
       xterm or vt100.

   5.19. Why is my PnP card not found (or found as unknown)?

   The reasons for this behavior are explained by the following
   email, posted to the FreeBSD general questions mailing list by
   Peter Wemm <peter@FreeBSD.org>, in answer to a question about an
   internal modem that was no longer found after an upgrade to
   FreeBSD 4.X (the comments in [] have been added to clarify the
   context).

     Note: The contents of this quotation has been updated from its
     original text.

     The PNP bios preconfigured it [the modem] and left it laying
     around in port space, so [in 3.X] the old-style ISA probes
     "found" it there.

     Under 4.0, the ISA code is much more PnP-centric. It was
     possible [in 3.X] for an ISA probe to find a "stray" device and
     then for the PNP device ID to match and then fail due to
     resource conflicts. So, it disables the programmable cards first
     so this double probing cannot happen. It also means that it
     needs to know the PnP IDs for supported PnP hardware. Making
     this more user tweakable is on the TODO list.

   To get the device working again requires finding its PnP ID and
   adding it to the list that the ISA probes use to identify PnP
   devices. This is obtained using pnpinfo(8) to probe the device,
   for example this is the output from pnpinfo(8) for an internal
   modem:

 # pnpinfo
 Checking for Plug-n-Play devices...

 Card assigned CSN #1
 Vendor ID PMC2430 (0x3024a341), Serial Number 0xffffffff
 PnP Version 1.0, Vendor Version 0
 Device Description: Pace 56 Voice Internal Plug & Play Modem

 Logical Device ID: PMC2430 0x3024a341 #0
         Device supports I/O Range Check
 TAG Start DF
     I/O Range 0x3f8 .. 0x3f8, alignment 0x8, len 0x8
         [16-bit addr]
     IRQ: 4  - only one type (true/edge)

   [more TAG lines elided]

 TAG End DF
 End Tag

 Successfully got 31 resources, 1 logical fdevs
 -- card select # 0x0001

 CSN PMC2430 (0x3024a341), Serial Number 0xffffffff

 Logical device #0
 IO:  0x03e8 0x03e8 0x03e8 0x03e8 0x03e8 0x03e8 0x03e8 0x03e8
 IRQ 5 0
 DMA 4 0
 IO range check 0x00 activate 0x01

   The information you require is in the Vendor ID line at the start
   of the output. The hexadecimal number in parentheses (0x3024a341
   in this example) is the PnP ID and the string immediately before
   this (PMC2430) is a unique ASCII ID.

   Alternatively, if pnpinfo(8) does not list the card in question,
   pciconf(8) can be used instead. This is part of the output from
   pciconf -vl for an onboard sound chip:

 # pciconf -vl
 chip1@pci0:31:5:        class=0x040100 card=0x00931028 chip=0x24158086 rev=0x02 hdr=0x00
     vendor   = 'Intel Corporation'
     device   = '82801AA 8xx Chipset AC'97 Audio Controller'
     class    = multimedia
     subclass = audio

   Here, you would use the chip value, 0x24158086.

   This information (Vendor ID or chip value) needs adding to the
   file /usr/src/sys/dev/sio/sio_isa.c.

   You should first make a backup of sio_isa.c just in case things go
   wrong. You will also need it to make the patch to submit with your
   PR (you are going to submit a PR, are you not?) then edit
   sio_isa.c and search for the line:

 static struct isa_pnp_id sio_ids[] = {

   Then scroll down to find the correct place to add the entry for
   your device. The entries look like this, and are sorted on the
   ASCII Vendor ID string which should be included in the comment to
   the right of the line of code along with all (if it will fit) or
   part of the Device Description from the output of pnpinfo(8):

 {0x0f804f3f, NULL},     /* OZO800f - Zoom 2812 (56k Modem) */
 {0x39804f3f, NULL},     /* OZO8039 - Zoom 56k flex */
 {0x3024a341, NULL},     /* PMC2430 - Pace 56 Voice Internal Modem */
 {0x1000eb49, NULL},     /* ROK0010 - Rockwell ? */
 {0x5002734a, NULL},     /* RSS0250 - 5614Jx3(G) Internal Modem */

   Add the hexadecimal Vendor ID for your device in the correct
   place, save the file, rebuild your kernel, and reboot. Your device
   should now be found as an sio device.

   5.20. Why do I get the error "nlist failed" when running, for
   example, top or systat?

   The problem is that the application you are trying to run is
   looking for a specific kernel symbol, but, for whatever reason,
   cannot find it; this error stems from one of two problems:

     * Your kernel and userland are not synchronized (i.e., you built
       a new kernel but did not do an installworld, or vice versa),
       and thus the symbol table is different from what the user
       application thinks it is. If this is the case, simply complete
       the upgrade process (see /usr/src/UPDATING for the correct
       sequence).

     * You are not using /boot/loader to load your kernel, but doing
       it directly from boot2 (see boot(8)). While there is nothing
       wrong with bypassing /boot/loader, it generally does a better
       job of making the kernel symbols available to user
       applications.

   5.21. Why does it take so long to connect to my computer via ssh
   or telnet?

   The symptom: there is a long delay between the time the TCP
   connection is established and the time when the client software
   asks for a password (or, in telnet(1)'s case, when a login prompt
   appears).

   The problem: more likely than not, the delay is caused by the
   server software trying to resolve the client's IP address into a
   hostname. Many servers, including the Telnet and SSH servers that
   come with FreeBSD, do this in order to, among other things, store
   the hostname in a log file for future reference by the
   administrator.

   The remedy: if the problem occurs whenever you connect from your
   computer (the client) to any server, the problem is with the
   client; likewise, if the problem only occurs when someone connects
   to your computer (the server) the problem is with the server.

   If the problem is with the client, the only remedy is to fix the
   DNS so the server can resolve it. If this is on a local network,
   consider it a server problem and keep reading; conversely, if this
   is on the global Internet, you will most likely need to contact
   your ISP and ask them to fix it for you.

   If the problem is with the server, and this is on a local network,
   you need to configure the server to be able to resolve
   address-to-hostname queries for your local address range. See the
   hosts(5) and named(8) manual pages for more information. If this
   is on the global Internet, the problem may be that your server's
   resolver is not functioning correctly. To check, try to look up
   another host -- say, www.yahoo.com. If it does not work, that is
   your problem.

   Following a fresh install of FreeBSD, it is also possible that
   domain and name server information is missing from
   /etc/resolv.conf. This will often cause a delay in SSH, as the
   option UseDNS is set to yes by default in the sshd_config file in
   /etc/ssh. If this is causing the problem, you will either need to
   fill in the missing information in /etc/resolv.conf or set UseDNS
   to no in sshd_config as a temporary workaround.

   5.22. What does "stray IRQ" mean?

   Stray IRQs are indications of hardware IRQ glitches, mostly from
   hardware that removes its interrupt request in the middle of the
   interrupt request acknowledge cycle.

   One has three options for dealing with this:

     * Live with the warnings. All except the first 5 per irq are
       suppressed anyway.

     * Break the warnings by changing the value of MAX_STRAY_LOG from
       5 to 0 in your platform's (e.g. i386) intr_machdep.c file and
       rebuild the new kernel and all the warnings will be
       suppressed.

     * Break the warnings by installing parallel port hardware that
       uses IRQ 7 and the PPP driver for it (this happens on most
       systems), and install an ide drive or other hardware that uses
       IRQ 15 and a suitable driver for it.

   5.23. Why does "file: table is full" show up repeatedly in
   dmesg(8)?

   This error message indicates you have exhausted the number of
   available file descriptors on your system. Please see the
   kern.maxfiles section of the Tuning Kernel Limits section of the
   Handbook for a discussion and solution.

   5.24. Why are "calcru: negative runtime" or "calcru: runtime went
   backwards" messages pounding the console?

   There is a known problem when enabling Intel Enhanced SpeedStep
   from the BIOS: it causes the kernel to start printing "calcru"
   messages like this:

 calcru: runtime went backwards from 6 usec to 3 usec for pid 37 (pagezero)
 calcru: runtime went backwards from 6 usec to 3 usec for pid 36 (vmdaemon)
 calcru: runtime went backwards from 170 usec to 138 usec for pid 35 (pagedaemon)
 calcru: runtime went backwards from 553 usec to 291 usec for pid 15 (swi6: task queue)
 calcru: runtime went backwards from 15521 usec to 10366 usec for pid 2 (g_event)
 calcru: runtime went backwards from 25 usec to 12 usec for pid 11 (swi1: net)
 calcru: runtime went backwards from 4417 usec to 3960 usec for pid 1 (init)
 calcru: runtime went backwards from 2084385 usec to 1793542 usec for pid 1 (init)
 calcru: runtime went backwards from 408 usec to 204 usec for pid 0 (swapper)

   It is because Intel SpeedStep (EIST) is incompatible with some
   motherboards.

   Workaround: Disable the EIST feature in the BIOS. You can still
   achieve ACPI-based processor frequency throttling by using
   powerd(8).

   5.25. Why does the clock on my computer keep incorrect time?

   Your computer has two or more clocks, and FreeBSD has chosen to
   use the wrong one.

   Run dmesg(8), and check for lines that contain Timecounter. The
   one with the highest quality value that FreeBSD chose.

 # dmesg | grep Timecounter
 Timecounter "i8254" frequency 1193182 Hz quality 0
 Timecounter "ACPI-fast" frequency 3579545 Hz quality 1000
 Timecounter "TSC" frequency 2998570050 Hz quality 800
 Timecounters tick every 1.000 msec

   You can confirm this by checking the kern.timecounter.hardware
   sysctl(3).

 # sysctl kern.timecounter.hardware
 kern.timecounter.hardware: ACPI-fast

   It may be a broken ACPI timer. The simplest solution is to disable
   the ACPI timer in /etc/loader.conf:

 debug.acpi.disabled="timer"

   Or the BIOS may modify the TSC clock--perhaps to change the speed
   of the processor when running from batteries, or going into a
   power saving mode, but FreeBSD is unaware of these adjustments,
   and appears to gain or lose time.

   In this example, the i8254 clock is also available, and can be
   selected by writing its name to the kern.timecounter.hardware
   sysctl(3).

 # sysctl -w kern.timecounter.hardware=i8254
 kern.timecounter.hardware: TSC -> i8254

   Your computer should now start keeping more accurate time.

   To have this change automatically run at boot time, add the
   following line to /etc/sysctl.conf:

 kern.timecounter.hardware=i8254

   5.26. Why did my laptop fail to correctly probe PC cards?

   This problem is common on laptops that boot more than one
   operating system. Some non-BSD operating systems leave PC card
   hardware in an inconsistent state. pccardd(8) will detect the card
   as ""(null)""(null)"" instead of its actual model.

   You must remove all power from the PC card slot to fully reset the
   hardware. Completely power off the laptop. (Do not suspend it, do
   not let it go into standby; the power needs to be completely off.)
   Wait a few moments, and reboot. Your PC card should work now.

   Some laptop hardware lies when it claims to be off. If the above
   does not work shut down, remove the battery, wait a moment,
   replace the battery, and reboot.

   5.27. Why does FreeBSD's boot loader display "Read error" and stop
   after the BIOS screen?

   FreeBSD's boot loader is incorrectly recognizing the hard drive's
   geometry. This must be manually set within fdisk(8) when creating
   or modifying FreeBSD's slice.

   The correct drive geometry values can be found within the
   machine's BIOS. Look for the number of cylinders, heads and
   sectors for the particular drive.

   Within sysinstall(8)'s fdisk, hit G to set the drive geometry.

   A dialog will pop up requesting the number of cylinders, heads and
   sectors. Type the numbers found from the BIOS separated by forward
   slashes. For example, values of 5000 cylinders, 250 heads, and 60
   sectors would be entered as 5000/250/60.

   Press Enter to set the values, and hit W to write the new
   partition table to the drive.

   5.28. Another operating system destroyed my Boot Manager. How do I
   get it back?

   Enter sysinstall(8) and choose Configure, then Fdisk. Select the
   disk the Boot Manager resided on with the Space key. Press W to
   write changes to the drive. A prompt will appear asking which boot
   loader to install. Select this, and it will be restored.

   5.29. What does the error "swap_pager: indefinite wait buffer:"
   mean?

   This means that a process is trying to page memory to disk, and
   the page attempt has hung trying to access the disk for more than
   20 seconds. It might be caused by bad blocks on the disk drive,
   disk wiring, cables, or any other disk I/O-related hardware. If
   the drive itself is actually bad, you will also see disk errors in
   /var/log/messages and in the output of dmesg. Otherwise, check
   your cables and connections.

   5.30. What are "UDMA ICRC" errors, and how do I fix them?

   The ata(4) driver reports "UDMA ICRC" errors when a DMA transfer
   to or from a drive is corrupted. The driver will retry the
   operation a few times. Should the retries fail, it will switch
   from DMA to the slower PIO mode of communication with the device.

   The problem can be caused by many factors, although perhaps the
   most common cause is faulty or incorrect cabling. Check that the
   ATA cables are undamaged and rated for the Ultra DMA mode in use.
   If you are using removable drive trays, they must also be
   compatible. Be sure that all connections are making good contact.
   Problems have also been noticed when an old drive is installed on
   the same ATA channel as an Ultra DMA 66 (or faster) drive. Lastly,
   these errors can indicate that the drive is failing. Most drive
   vendors provide testing software for their drives, so test your
   drive, and, if necessary, back up your data and replace it.

   The atacontrol(8) utility can be used to show and select the DMA
   or PIO modes used for each ATA device. In particular, atacontrol
   mode channel will show the modes in use on a particular ATA
   channel, where the primary channel is numbered 0, and so on.

   5.31. What is a "lock order reversal"?

   An answer for this question can be found in the FreeBSD Glosssary,
   see LOR.

   5.32. What does "Called ... with the following non-sleepable locks
   held" mean?

   This means that a function that may sleep was called while a mutex
   (or other unsleepable) lock was held.

   The reason this is an error is because mutexes are not intended to
   be held for long periods of time; they are supposed to only be
   held to maintain short periods of synchronization. This
   programming contract allows device drivers to use mutexes to
   synchronize with the rest of the kernel during interrupts.
   Interrupts (under FreeBSD) may not sleep. Hence it is imperative
   that no subsystem in the kernel block for an extended period while
   holding a mutex.

   To catch such errors, assertions may be added to the kernel that
   interact with the witness(4) subsystem to emit a warning or fatal
   error (depending on the system configuration) when a potentially
   blocking call is made while holding a mutex.

   In summary, such warnings are non-fatal, however with unfortunate
   timing they could cause undesirable effects ranging from a minor
   blip in the system's responsiveness to a complete system lockup.

   5.33. Why does buildworld/installworld die with the message
   "touch: not found"?

   This error does not mean that the touch(1) utility is missing. The
   error is instead probably due to the dates of the files being set
   sometime in the future. If your CMOS-clock is set to local time
   you need to run the command adjkerntz -i to adjust the kernel
   clock when booting into single user mode.

     --------------------------------------------------------------

                   Chapter 6 Commercial Applications

     Note: This section is still very sparse, though we are hoping,
     of course, that companies will add to it! :) The FreeBSD group
     has no financial interest in any of the companies listed here
     but simply lists them as a public service (and feels that
     commercial interest in FreeBSD can have very positive effects on
     FreeBSD's long-term viability). We encourage commercial software
     vendors to send their entries here for inclusion. See the
     Vendors page for a longer list.

   6.1. Where can I get an Office Suite for FreeBSD?

   6.2. Where can I get Motif(R) for FreeBSD?

   6.3. Where can I get CDE for FreeBSD?

   6.4. Are there any Database systems for FreeBSD?

   6.5. Can I run Oracle(R) on FreeBSD?

   6.1. Where can I get an Office Suite for FreeBSD?

   The open-source OpenOffice.org office suite works natively on
   FreeBSD. The Linux version of StarOffice, the value-added
   closed-source version of OpenOffice.org, also works on FreeBSD.

   FreeBSD also includes a variety of text editors, spreadsheets, and
   drawing programs in the Ports Collection.

   6.2. Where can I get Motif(R) for FreeBSD?

   The Open Group has released the source code to Motif 2.2.2. You
   can install the x11-toolkits/open-motif package, or compile it
   from ports. Refer to the ports section of the Handbook for more
   information on how to do this.

     Note: The Open Motif distribution only allows redistribution if
     it is running on an open source operating system.

   In addition, there are commercial distributions of the Motif
   software available. These, however, are not for free, but their
   license allows them to be used in closed-source software. Contact
   Apps2go for the least expensive ELF Motif 2.1.20 distribution for
   FreeBSD (i386).

   There are two distributions, the "development edition" and the
   "runtime edition" (for much less). These distributions includes:

     * OSF/Motif manager, xmbind, panner, wsm.

     * Development kit with uil, mrm, xm, xmcxx, include and Imake
       files.

     * Static and dynamic ELF libraries.

     * Demonstration applets.

   Be sure to specify that you want the FreeBSD version of Motif when
   ordering (do not forget to mention the architecture you want too)!
   Versions for NetBSD and OpenBSD are also sold by Apps2go. This is
   currently a FTP only download.

   More info

           Apps2go WWW page

   or

           <sales@apps2go.com> or <support@apps2go.com>

   or

           phone (817) 431 8775 or +1 817 431-8775

   6.3. Where can I get CDE for FreeBSD?

   Xi Graphics used to sell CDE for FreeBSD, but no longer do.

   KDE is an open source X11 desktop which is similar to CDE in many
   respects. You might also like the look and feel of xfce. KDE and
   xfce are both in the ports system.

   6.4. Are there any Database systems for FreeBSD?

   Yes! See the Commercial Vendors section of FreeBSD's Web site.

   Also see the Databases section of the Ports Collection.

   6.5. Can I run Oracle(R) on FreeBSD?

   Yes. The following pages tell you exactly how to set up Linux
   Oracle on FreeBSD:

     * http://www.unixcities.com/oracle/index.html

     * http://www.shadowcom.net/freebsd-oracle9i/

     --------------------------------------------------------------

                      Chapter 7 User Applications

   7.1. So, where are all the user applications?

   7.2. How do I configure INN (Internet News) for my machine?

   7.3. Does FreeBSD support Java(TM)?

   7.4. Why can I not build this port on my 6.X or 7.X-STABLE
   machine?

   7.5. I just tried to build INDEX using make index, and it failed.
   Why?

   7.6. Why is CVSup not integrated in the main FreeBSD tree?

   7.7. I updated the sources, now how do I update my installed
   ports?

   7.8. Do I need to recompile every port each time I perform a major
   version update?

   7.9. Do I need to recompile every port each time I perform a minor
   version update?

   7.10. Why is /bin/sh so minimal? Why does FreeBSD not use bash or
   another shell?

   7.11. Why do Netscape and Opera take so long to start?

   7.12. I updated parts of the Ports Collection using CVSup, and now
   many ports fail to build with mysterious error messages! What
   happened? Is the Ports Collection broken in some major way?

   7.13. How do I create audio CDs from my MIDI files?

   7.1. So, where are all the user applications?

   Please take a look at the ports page for info on software packages
   ported to FreeBSD. The list currently tops 20,000 and is growing
   daily, so come back to check often or subscribe to the FreeBSD
   announcements mailing list for periodic updates on new entries.

   Most ports should work on the 6.X, 7.X and 8.X branches. Each time
   a FreeBSD release is made, a snapshot of the ports tree at the
   time of release in also included in the ports/ directory.

   We also support the concept of a "package", essentially no more
   than a compressed binary distribution with a little extra
   intelligence embedded in it for doing whatever custom installation
   work is required. A package can be installed and uninstalled again
   easily without having to know the gory details of which files it
   includes.

   Use the Packages package installation menu in sysinstall(8) (under
   the Configure menu item) or invoke the pkg_add(1) command on the
   specific package files you are interested in installing. Package
   files can usually be identified by their .tbz suffix and CD-ROM
   distribution people will have a packages/All directory on their CD
   which contains such files. They can also be downloaded over the
   net for various versions of FreeBSD at the following locations:

   for 6.X-RELEASE/6-STABLE

           ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/i386/packages-6-stable

   for 7.X-RELEASE/7-STABLE

           ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/i386/packages-7-stable

   for 8-CURRENT

           ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/i386/packages-8-current

   or your nearest local mirror site.

   Note that all ports may not be available as packages since new
   ones are constantly being added. It is always a good idea to check
   back periodically to see which packages are available at the
   ftp.FreeBSD.org master site.

   7.2. How do I configure INN (Internet News) for my machine?

   After installing the news/inn package or port, an excellent place
   to start is Dave Barr's INN Page where you will find the INN FAQ.

   7.3. Does FreeBSD support Java(TM)?

   Yes. Please see http://www.FreeBSD.org/java/.

   7.4. Why can I not build this port on my 6.X or 7.X-STABLE
   machine?

   If you are running a FreeBSD version that lags significantly
   behind -CURRENT or -STABLE, you may need to update your Ports
   Collection; see the Keeping Up section of the Porter's Handbook
   for further information on how to do this. If you are up to date,
   then someone might have committed a change to the port which works
   for -CURRENT but which broke the port for -STABLE. Please submit a
   bug report on this with the send-pr(1) command, since the Ports
   Collection is supposed to work for both the -CURRENT and -STABLE
   branches.

   7.5. I just tried to build INDEX using make index, and it failed.
   Why?

   First, always make sure that you have a completely up-to-date
   Ports Collection. Errors that affect building INDEX from an
   up-to-date copy of the Ports Collection are high-visibility and
   are thus almost always fixed immediately.

   However, if you are up-to-date, perhaps you are seeing another
   problem. make index has a known bug in dealing with incomplete
   copies of the Ports Collection. It assumes that you have a local
   copy of every single port that every other port that you have a
   local copy of depends on. To explain, if you have a copy of
   foo/bar on your disk, and foo/bar depends on baz/quux, then you
   must also have a copy of baz/quux on your disk, and the ports
   baz/quux depends on, and so on. Otherwise, make index has
   insufficient information to create its dependency tree.

   This is particularly a problem for FreeBSD users who utilize
   cvsup(1) (or csup(1)) to track the Ports Collection but choose not
   to install certain categories by specifying them in refuse. In
   theory, one should be able to refuse categories, but in practice
   there are too many ports that depend on ports in other categories.
   Until someone comes up with a solution for this problem, the
   general rule is is that if you want to build INDEX, you must have
   a complete copy of the Ports Collection.

   There are rare cases where INDEX will not build due to odd cases
   involving WITH_* or WITHOUT_* variables being set in make.conf. If
   you suspect that this is the case, please try to make INDEX with
   those make variables turned off before reporting it to FreeBSD
   ports mailing list.

   7.6. Why is CVSup not integrated in the main FreeBSD tree?

   The FreeBSD base system is designed as self-hosting -- it should
   be possible to build the whole operating system starting with a
   very limited set of tools. Thus, the actual build tools needed to
   compile the FreeBSD sources are bundled with the sources
   themselves. This includes a C compiler (gcc(1)), make(1), awk(1),
   and similar tools.

   Since CVSup is written in Modula-3, adding it to the FreeBSD base
   system would also require adding and maintaining a Modula-3
   compiler. This would lead to both an increase in the disk space
   consumed by the FreeBSD sources and additional maintenance work.
   Thus, it is much easier for both the developers and users to keep
   CVSup as a separate port, which can be easily installed as a
   package bundled on the FreeBSD installation CDs.

   However, FreeBSD users are not without an integrated CVSup
   compatible client anymore since FreeBSD 6.2-RELEASE. Thanks to
   Maxime Henrion <mux@FreeBSD.org>, CVSup was rewritten in C as
   csup(1) and it is the part of the base system by now. Although it
   does not implement all the features of CVSup at the moment, it is
   good enough (and really fast!) to keep your sources synchronized.
   For systems earlier than 6.2, it can be installed as a port or
   package (see net/csup).

   7.7. I updated the sources, now how do I update my installed
   ports?

   FreeBSD does not include a port upgrading tool, but it does have
   some tools to make the upgrade process somewhat easier. You can
   also install additional tools to simplify port handling, see the
   Upgrading Ports section in the FreeBSD Handbook.

   7.8. Do I need to recompile every port each time I perform a major
   version update?

   By all means! While a recent system will run with software
   compiled under an older release, you will end up with things
   randomly crashing and failing to work once you start installing
   other ports or updating a portion of what you already have.

   When the system is upgraded, various shared libraries, loadable
   modules, and other parts of the system will be replaced with newer
   versions. Applications linked against the older versions may fail
   to start or, in other cases, fail to function properly.

   For more information, see the section on upgrades in the FreeBSD
   Handbook.

   7.9. Do I need to recompile every port each time I perform a minor
   version update?

   In general, no. FreeBSD developers do their utmost to guarantee
   binary compatibility across all releases with the same major
   version number. Any exceptions will be documented in the Release
   Notes, and advice given there should be followed.

   7.10. Why is /bin/sh so minimal? Why does FreeBSD not use bash or
   another shell?

   Because POSIX(R) says that there shall be such a shell.

   The more complicated answer: many people need to write shell
   scripts which will be portable across many systems. That is why
   POSIX specifies the shell and utility commands in great detail.
   Most scripts are written in Bourne shell, and because several
   important programming interfaces (make(1), system(3), popen(3),
   and analogues in higher-level scripting languages like Perl and
   Tcl) are specified to use the Bourne shell to interpret commands.
   Because the Bourne shell is so often and widely used, it is
   important for it to be quick to start, be deterministic in its
   behavior, and have a small memory footprint.

   The existing implementation is our best effort at meeting as many
   of these requirements simultaneously as we can. In order to keep
   /bin/sh small, we have not provided many of the convenience
   features that other shells have. That is why the Ports Collection
   includes more featureful shells like bash, scsh, tcsh, and zsh.
   (You can compare for yourself the memory utilization of all these
   shells by looking at the "VSZ" and "RSS" columns in a ps -u
   listing.)

   7.11. Why do Netscape and Opera take so long to start?

   The usual answer is that DNS on your system is misconfigured. Both
   Netscape and Opera perform DNS checks when starting up. The
   browser will not appear on your desktop until the program either
   gets a response or determines that the system has no network
   connection.

   7.12. I updated parts of the Ports Collection using CVSup, and now
   many ports fail to build with mysterious error messages! What
   happened? Is the Ports Collection broken in some major way?

   If you only update parts of the Ports Collection, using one of its
   CVSup subcollections and not the ports-all CVSup collection, you
   should always update the ports-base subcollection too! The reasons
   are described in the Handbook.

   7.13. How do I create audio CDs from my MIDI files?

   To create audio CDs from MIDI files, first install
   audio/timidity++ from ports then install manually the GUS patches
   set by Eric A. Welsh, available at
   http://alleg.sourceforge.net/digmid.html. After TiMidity++ has
   been installed properly, MIDI files may be converted to WAV files
   with the following command line:

 % timidity -Ow -s 44100 -o /tmp/juke/01.wav 01.mid

   The WAV files can then be converted to other formats or burned
   onto audio CDs, as described in the FreeBSD Handbook.

     --------------------------------------------------------------

                     Chapter 8 Kernel Configuration

   8.1. I would like to customize my kernel. Is it difficult?

   8.2. My kernel compiles fail because _hw_float is missing. How do
   I solve this problem?

   8.3. Why is my kernel so big (over 10 MB)?

   8.4. Why do I get interrupt conflicts with multi-port serial code?

   8.5. Why does every kernel I try to build fail to compile, even
   GENERIC?

   8.6. How can I verify which scheduler is in use on a running
   system?

   8.7. What is kern.sched.quantum?

   8.1. I would like to customize my kernel. Is it difficult?

   Not at all! Check out the kernel config section of the Handbook.

     Note: The new kernel will be installed to the /boot/kernel
     directory along with its modules, while the old kernel and its
     modules will be moved to the /boot/kernel.old directory, so if
     you make a mistake the next time you play with your
     configuration you can boot the previous version of your kernel.

   8.2. My kernel compiles fail because _hw_float is missing. How do
   I solve this problem?

   You probably removed npx0 (see npx(4)) from your kernel
   configuration file because you do not have a math co-processor.
   The npx0 device is MANDATORY. Somewhere inside your hardware lies
   a device that provides hardware floating-point support, even if it
   is no longer a separate device as used in the good old 386 days.
   You must include the npx0 device. Even if you manage to build a
   kernel without npx0 support, it will not boot anyway.

   8.3. Why is my kernel so big (over 10 MB)?

   Chances are, you compiled your kernel in debug mode. Kernels built
   in debug mode contain many symbols that are used for debugging,
   thus greatly increasing the size of the kernel. Note that there
   will be little or no performance decrease from running a debug
   kernel, and it is useful to keep one around in case of a system
   panic.

   However, if you are running low on disk space, or you simply do
   not want to run a debug kernel, make sure that both of the
   following are true:

     * You do not have a line in your kernel configuration file that
       reads:

 makeoptions DEBUG=-g

     * You are not running config(8) with the -g option.

   Either of the above settings will cause your kernel to be built in
   debug mode. As long as you make sure you follow the steps above,
   you can build your kernel normally, and you should notice a fairly
   large size decrease; most kernels tend to be around 1.5 MB to
   2 MB.

   8.4. Why do I get interrupt conflicts with multi-port serial code?

   When I compile a kernel with multi-port serial code, it tells me
   that only the first port is probed and the rest skipped due to
   interrupt conflicts. How do I fix this?

   The problem here is that FreeBSD has code built-in to keep the
   kernel from getting trashed due to hardware or software conflicts.
   The way to fix this is to leave out the IRQ settings on all but
   one port. Here is an example:

 #
 # Multiport high-speed serial line - 16550 UARTS
 #
 device sio2 at isa? port 0x2a0 tty irq 5 flags 0x501 vector siointr
 device sio3 at isa? port 0x2a8 tty flags 0x501 vector siointr
 device sio4 at isa? port 0x2b0 tty flags 0x501 vector siointr
 device sio5 at isa? port 0x2b8 tty flags 0x501 vector siointr

   8.5. Why does every kernel I try to build fail to compile, even
   GENERIC?

   There are a number of possible causes for this problem. They are,
   in no particular order:

     * You are not using the make buildkernel and make installkernel
       targets, and your source tree is different from the one used
       to build the currently running system (e.g., you are compiling
       8.0-RELEASE on a 7.2-RELEASE system). If you are attempting an
       upgrade, please read the /usr/src/UPDATING file, paying
       particular attention to the "COMMON ITEMS" section at the end.

     * You are using the make buildkernel and make installkernel
       targets, but you failed to assert the completion of the make
       buildworld target. The make buildkernel target relies on files
       generated by the make buildworld target to complete its job
       correctly.

     * Even if you are trying to build FreeBSD-STABLE, it is possible
       that you fetched the source tree at a time when it was either
       being modified, or broken for other reasons; only releases are
       absolutely guaranteed to be buildable, although FreeBSD-STABLE
       builds fine the majority of the time. If you have not already
       done so, try re-fetching the source tree and see if the
       problem goes away. Try using a different server in case the
       one you are using is having problems.

   8.6. How can I verify which scheduler is in use on a running
   system?

   Check for the existence of the kern.sched.quantum sysctl. If you
   have it, you should see something like this:

 % sysctl kern.sched.quantum
 kern.sched.quantum: 99960

   If the kern.sched.quantum sysctl exists, you are using the 4BSD
   scheduler (sched_4bsd(4)). If not, you will get an error printed
   by sysctl(8) (which you can safely ignore):

 % sysctl kern.sched.quantum
 sysctl: unknown oid 'kern.sched.quantum'

   The name of the scheduler currently being used is directly
   available as the value of the kern.sched.name sysctl:

 % sysctl kern.sched.name
 kern.sched.name: 4BSD

   8.7. What is kern.sched.quantum?

   kern.sched.quantum is the maximum number of ticks a process can
   run without being preempted. It is specific to the 4BSD scheduler,
   so you can use its presence or absence to determine which
   scheduler is in use.

     --------------------------------------------------------------

            Chapter 9 Disks, File Systems, and Boot Loaders

   9.1. How can I add my new hard disk to my FreeBSD system?

   9.2. How do I move my system over to my huge new disk?

   9.3. Will a "dangerously dedicated" disk endanger my health?

   9.4. Which partitions can safely use Soft Updates? I have heard
   that Soft Updates on / can cause problems.

   9.5. What is inappropriate about my ccd(4)?

   9.6. Why can I not edit the disk label on my ccd(4)?

   9.7. Can I mount other foreign file systems under FreeBSD?

   9.8. How do I mount a secondary DOS partition?

   9.9. Is there a cryptographic file system for FreeBSD?

   9.10. How can I use the Windows NT(R) loader to boot FreeBSD?

   9.11. How do I boot FreeBSD and Linux from LILO?

   9.12. How do I boot FreeBSD and Linux using GRUB?

   9.13. How do I boot FreeBSD and Linux using BootEasy?

   9.14. How do I change the boot prompt from ??? to something more
   meaningful?

   9.15. I have a new removable drive, how do I use it?

   9.16. Why do I get "Incorrect super block" when mounting a CD-ROM?

   9.17. Why do I get "Device not configured" when mounting a CD-ROM?

   9.18. Why do all non-English characters in filenames show up as
   "?" on my CDs when mounted in FreeBSD?

   9.19. I burned a CD under FreeBSD and now I can not read it under
   any other operating system. Why?

   9.20. How can I create an image of a data CD?

   9.21. Why can I not mount an audio CD?

   9.22. How do I mount a multi-session CD?

   9.23. How do I let ordinary users mount floppies, CD-ROMs and
   other removable media?

   9.24. The du and df commands show different amounts of disk space
   available. What is going on?

   9.25. How can I add more swap space?

   9.26. Why does FreeBSD see my disk as smaller than the
   manufacturer says it is?

   9.27. How is it possible for a partition to be more than 100%
   full?

   9.1. How can I add my new hard disk to my FreeBSD system?

   See the Adding Disks section in the FreeBSD Handbook.

   9.2. How do I move my system over to my huge new disk?

   The best way is to reinstall the OS on the new disk, then move the
   user data over. This is highly recommended if you have been
   tracking -STABLE for more than one release, or have updated a
   release instead of installing a new one. You can install booteasy
   on both disks with boot0cfg(8), and dual boot them until you are
   happy with the new configuration. Skip the next paragraph to find
   out how to move the data after doing this.

   Should you decide not to do a fresh install, you need to partition
   and label the new disk with either sysinstall(8), or fdisk(8) and
   disklabel(8). You should also install booteasy on both disks with
   boot0cfg(8), so that you can dual boot to the old or new system
   after the copying is done. See the formatting-media article for
   details on this process.

   Now you have the new disk set up, and are ready to move the data.
   Unfortunately, you cannot just blindly copy the data. Things like
   device files (in /dev), flags, and links tend to screw that up.
   You need to use tools that understand these things, which means
   dump(8). Although it is suggested that you move the data in single
   user mode, it is not required.

   You should never use anything but dump(8) and restore(8) to move
   the root file system. The tar(1) command may work -- then again,
   it may not. You should also use dump(8) and restore(8) if you are
   moving a single partition to another empty partition. The sequence
   of steps to use dump to move a partitions data to a new partition
   is:

    1. newfs the new partition.

    2. mount it on a temporary mount point.

    3. cd to that directory.

    4. dump the old partition, piping output to the new one.

   For example, if you are going to move root to /dev/ad1s1a, with
   /mnt as the temporary mount point, it is:

 # newfs /dev/ad1s1a
 # mount /dev/ad1s1a /mnt
 # cd /mnt
 # dump 0af - / | restore rf -

   Rearranging your partitions with dump takes a bit more work. To
   merge a partition like /var into its parent, create the new
   partition large enough for both, move the parent partition as
   described above, then move the child partition into the empty
   directory that the first move created:

 # newfs /dev/ad1s1a
 # mount /dev/ad1s1a /mnt
 # cd /mnt
 # dump 0af - / | restore rf -
 # cd var
 # dump 0af - /var | restore rf -

   To split a directory from its parent, say putting /var on its own
   partition when it was not before, create both partitions, then
   mount the child partition on the appropriate directory in the
   temporary mount point, then move the old single partition:

 # newfs /dev/ad1s1a
 # newfs /dev/ad1s1d
 # mount /dev/ad1s1a /mnt
 # mkdir /mnt/var
 # mount /dev/ad1s1d /mnt/var
 # cd /mnt
 # dump 0af - / | restore rf -

   You might prefer cpio(1), pax(1), tar(1) to dump(8) for user data.
   At the time of this writing, these are known to lose file flag
   information, so use them with caution.

   9.3. Will a "dangerously dedicated" disk endanger my health?

   The installation procedure allows you to chose two different
   methods in partitioning your hard disk(s). The default way makes
   it compatible with other operating systems on the same machine, by
   using fdisk(8) table entries (called "slices" in FreeBSD), with a
   FreeBSD slice that employs partitions of its own. Optionally, one
   can chose to install a boot-selector to switch between the
   possible operating systems on the disk(s). The alternative uses
   the entire disk for FreeBSD, and makes no attempt to be compatible
   with other operating systems.

   So why it is called "dangerous"? A disk in this mode does not
   contain what normal PC utilities would consider a valid fdisk(8)
   table. Depending on how well they have been designed, they might
   complain at you once they are getting in contact with such a disk,
   or even worse, they might damage the BSD bootstrap without even
   asking or notifying you. In addition, the "dangerously dedicated"
   disk's layout is known to confuse many BIOSes, including those
   from AWARD (e.g. as found in HP Netserver and Micronics systems as
   well as many others) and Symbios/NCR (for the popular 53C8xx range
   of SCSI controllers). This is not a complete list, there are more.
   Symptoms of this confusion include the "read error" message
   printed by the FreeBSD bootstrap when it cannot find itself, as
   well as system lockups when booting.

   Why have this mode at all then? It only saves a few kbytes of disk
   space, and it can cause real problems for a new installation.
   "Dangerously dedicated" mode's origins lie in a desire to avoid
   one of the most common problems plaguing new FreeBSD installers --
   matching the BIOS "geometry" numbers for a disk to the disk
   itself.

   "Geometry" is an outdated concept, but one still at the heart of
   the PC's BIOS and its interaction with disks. When the FreeBSD
   installer creates slices, it has to record the location of these
   slices on the disk in a fashion that corresponds with the way the
   BIOS expects to find them. If it gets it wrong, you will not be
   able to boot.

   "Dangerously dedicated" mode tries to work around this by making
   the problem simpler. In some cases, it gets it right. But it is
   meant to be used as a last-ditch alternative -- there are better
   ways to solve the problem 99 times out of 100.

   So, how do you avoid the need for "DD" mode when you are
   installing? Start by making a note of the geometry that your BIOS
   claims to be using for your disks. You can arrange to have the
   kernel print this as it boots by specifying -v at the boot:
   prompt, or using boot -v in the loader. Just before the installer
   starts, the kernel will print a list of BIOS geometries. Do not
   panic -- wait for the installer to start and then use scrollback
   to read the numbers. Typically the BIOS disk units will be in the
   same order that FreeBSD lists your disks, first IDE, then SCSI.

   When you are slicing up your disk, check that the disk geometry
   displayed in the FDISK screen is correct (ie. it matches the BIOS
   numbers); if it is wrong, use the G key to fix it. You may have to
   do this if there is absolutely nothing on the disk, or if the disk
   has been moved from another system. Note that this is only an
   issue with the disk that you are going to boot from; FreeBSD will
   sort itself out just fine with any other disks you may have.

   Once you have got the BIOS and FreeBSD agreeing about the geometry
   of the disk, your problems are almost guaranteed to be over, and
   with no need for "DD" mode at all. If, however, you are still
   greeted with the dreaded "read error" message when you try to
   boot, it is time to cross your fingers and go for it -- there is
   nothing left to lose.

   To return a "dangerously dedicated" disk for normal PC use, there
   are basically two options. The first is, you write enough NULL
   bytes over the MBR to make any subsequent installation believe
   this to be a blank disk. You can do this for example with the
   following command:

 # dd if=/dev/zero of=/dev/rda0 count=15

   Alternatively, the undocumented DOS "feature"

 C:\> fdisk /mbr

   will to install a new master boot record as well, thus clobbering
   the BSD bootstrap.

   9.4. Which partitions can safely use Soft Updates? I have heard
   that Soft Updates on / can cause problems.

   Short answer: you can usually use Soft Updates safely on all
   partitions.

   Long answer: There used to be some concern over using Soft Updates
   on the root partition. Soft Updates has two characteristics that
   caused this. First, a Soft Updates partition has a small chance of
   losing data during a system crash. (The partition will not be
   corrupted; the data will simply be lost.) Also, Soft Updates can
   cause temporary space shortages.

   When using Soft Updates, the kernel can take up to thirty seconds
   to actually write changes to the physical disk. If you delete a
   large file, the file still resides on disk until the kernel
   actually performs the deletion. This can cause a very simple race
   condition. Suppose you delete one large file and immediately
   create another large file. The first large file is not yet
   actually removed from the physical disk, so the disk might not
   have enough room for the second large file. You get an error that
   the partition does not have enough space, although you know
   perfectly well that you just released a large chunk of space! When
   you try again mere seconds later, the file creation works as you
   expect. This has left more than one user scratching his head and
   doubting his sanity, the FreeBSD file system, or both.

   If a system should crash after the kernel accepts a chunk of data
   for writing to disk, but before that data is actually written out,
   data could be lost or corrupted. This risk is extremely small, but
   generally manageable. Use of IDE write caching greatly increases
   this risk; it is strongly recommended that you disable IDE write
   caching when using Soft Updates.

   These issues affect all partitions using Soft Updates. So, what
   does this mean for the root partition?

   Vital information on the root partition changes very rarely. Files
   such as /boot/kernel/kernel and the contents of /etc only change
   during system maintenance, or when users change their passwords.
   If the system crashed during the thirty-second window after such a
   change is made, it is possible that data could be lost. This risk
   is negligible for most applications, but you should be aware that
   it exists. If your system cannot tolerate this much risk, do not
   use Soft Updates on the root file system!

   / is traditionally one of the smallest partitions. If you put the
   /tmp directory on / and you have a busy /tmp, you might see
   intermittent space problems. Symlinking /tmp to /var/tmp will
   solve this problem.

   9.5. What is inappropriate about my ccd(4)?

   The symptom of this is:

 # ccdconfig -C
 ccdconfig: ioctl (CCDIOCSET): /dev/ccd0c: Inappropriate file type or format

   This usually happens when you are trying to concatenate the c
   partitions, which default to type unused. The ccd(4) driver
   requires the underlying partition type to be FS_BSDFFS. Edit the
   disk label of the disks you are trying to concatenate and change
   the types of partitions to 4.2BSD.

   9.6. Why can I not edit the disk label on my ccd(4)?

   The symptom of this is:

 # disklabel ccd0
 (it prints something sensible here, so let us try to edit it)
 # disklabel -e ccd0
 (edit, save, quit)
 disklabel: ioctl DIOCWDINFO: No disk label on disk;
 use "disklabel -r" to install initial label

   This is because the disk label returned by ccd(4) is actually a
   "fake" one that is not really on the disk. You can solve this
   problem by writing it back explicitly, as in:

 # disklabel ccd0 > /tmp/disklabel.tmp
 # disklabel -Rr ccd0 /tmp/disklabel.tmp
 # disklabel -e ccd0
 (this will work now)

   9.7. Can I mount other foreign file systems under FreeBSD?

   FreeBSD supports a variety of other file systems.

   UFS

           UFS CD-ROMs can be mounted directly on FreeBSD. Mounting
           disk partitions from Digital UNIX and other systems that
           support UFS may be more complex, depending on the details
           of the disk partitioning for the operating system in
           question.

   ext2/ext3

           FreeBSD supports ext2fs and ext3fs partitions. See
           mount_ext2fs(8) for more information.

   NTFS

           FreeBSD includes a read-only NTFS driver. For more
           information, see mount_ntfs(8). A port of ntfs-3g supports
           write operations on NTFS (see sysutils/fusefs-ntfs).

   FAT

           FreeBSD includes a read-write FAT driver. For more
           information, see mount_msdosfs(8).

   ReiserFS

           FreeBSD includes a read-only ReiserFS driver. For more
           information, see mount_reiserfs(8).

   ZFS

           As of this writing, FreeBSD includes a port of Sun(TM)'s
           ZFS driver. The current recommendation is to use it only
           on amd64 platforms with sufficient memory. For more
           information, see zfs(8).

   FreeBSD also supports network file systems such as NFS (see
   mount_nfs(8)), NetWare (see mount_nwfs(8)), and Microsoft-style
   SMB file systems (see mount_smbfs(8)). You can find ports based on
   FUSE (sysutils/fusefs-kmod) for many other file systems.

   9.8. How do I mount a secondary DOS partition?

   The secondary DOS partitions are found after all the primary
   partitions. For example, if you have an "E" partition as the
   second DOS partition on the second SCSI drive, there will be a
   device file for "slice 5" in /dev, so simply mount it:

 # mount -t msdosfs /dev/da1s5 /dos/e

   9.9. Is there a cryptographic file system for FreeBSD?

   Yes. You can use either gbde(8) or geli(8), see the Encrypting
   Disk Partitions section of the FreeBSD Handbook.

   9.10. How can I use the Windows NT(R) loader to boot FreeBSD?

   The general idea is that you copy the first sector of your native
   root FreeBSD partition into a file in the DOS/Windows NT
   partition. Assuming you name that file something like
   c:\bootsect.bsd (inspired by c:\bootsect.dos), you can then edit
   the c:\boot.ini file to come up with something like this:

 [boot loader]
 timeout=30
 default=multi(0)disk(0)rdisk(0)partition(1)\WINDOWS
 [operating systems]
 multi(0)disk(0)rdisk(0)partition(1)\WINDOWS="Windows NT"
 C:\BOOTSECT.BSD="FreeBSD"
 C:\="DOS"

   If FreeBSD is installed on the same disk as the Windows NT boot
   partition simply copy /boot/boot1 to C:\BOOTSECT.BSD. However, if
   FreeBSD is installed on a different disk /boot/boot1 will not
   work, /boot/boot0 is needed.

   /boot/boot0 needs to be installed using sysinstall(8) by selecting
   the FreeBSD boot manager on the screen which asks if you wish to
   use a boot manager. This is because /boot/boot0 has the partition
   table area filled with NULL characters but sysinstall(8) copies
   the partition table before copying /boot/boot0 to the MBR.

     Warning: Do not simply copy /boot/boot0 instead of /boot/boot1;
     you will overwrite your partition table and render your computer
     un-bootable!

   When the FreeBSD boot manager runs it records the last OS booted
   by setting the active flag on the partition table entry for that
   OS and then writes the whole 512-bytes of itself back to the MBR
   so if you just copy /boot/boot0 to C:\BOOTSECT.BSD then it writes
   an empty partition table, with the active flag set on one entry,
   to the MBR.

   9.11. How do I boot FreeBSD and Linux from LILO?

   If you have FreeBSD and Linux on the same disk, just follow LILO's
   installation instructions for booting a non-Linux operating
   system. Very briefly, these are:

   Boot Linux, and add the following lines to /etc/lilo.conf:

 other=/dev/hda2
         table=/dev/hda
         label=FreeBSD

   (the above assumes that your FreeBSD slice is known to Linux as
   /dev/hda2; tailor to suit your setup). Then, run lilo as root and
   you should be done.

   If FreeBSD resides on another disk, you need to add
   loader=/boot/chain.b to the LILO entry. For example:

 other=/dev/dab4
         table=/dev/dab
         loader=/boot/chain.b
         label=FreeBSD

   In some cases you may need to specify the BIOS drive number to the
   FreeBSD boot loader to successfully boot off the second disk. For
   example, if your FreeBSD SCSI disk is probed by BIOS as BIOS disk
   1, at the FreeBSD boot loader prompt you need to specify:

 Boot: 1:da(0,a)/boot/kernel/kernel

   You can configure boot(8) to automatically do this for you at boot
   time.

   The Linux+FreeBSD mini-HOWTO is a good reference for FreeBSD and
   Linux interoperability issues.

   9.12. How do I boot FreeBSD and Linux using GRUB?

   Booting FreeBSD using GRUB is very simple. Just add the following
   to your configuration file /boot/grub/menu.lst (or
   /boot/grub/grub.conf in some systems, e.g. Red Hat Linux and its
   derivatives).

 title FreeBSD 6.1
         root (hd0,a)
         kernel /boot/loader
          

   Where hd0,a points to your root partition on the first disk. If
   you need to specify which slice number should be used, use
   something like this (hd0,2,a). By default, if the slice number is
   omitted, GRUB searches the first slice which has a partition.

   9.13. How do I boot FreeBSD and Linux using BootEasy?

   Install LILO at the start of your Linux boot partition instead of
   in the Master Boot Record. You can then boot LILO from BootEasy.

   If you are running Windows and Linux this is recommended anyway,
   to make it simpler to get Linux booting again if you should need
   to reinstall Windows (which is a Jealous Operating System, and
   will bear no other Operating Systems in the Master Boot Record).

   9.14. How do I change the boot prompt from ??? to something more
   meaningful?

   You can not do that with the standard boot manager without
   rewriting it. There are a number of other boot managers in the
   sysutils ports category that provide this functionality.

   9.15. I have a new removable drive, how do I use it?

   Whether it is a removable drive like a Zip or an EZ drive (or even
   a floppy, if you want to use it that way), or a new hard disk,
   once it is installed and recognized by the system, and you have
   your cartridge/floppy/whatever slotted in, things are pretty much
   the same for all devices.

   (this section is based on Mark Mayo's ZIP FAQ)

   If it is a ZIP drive or a floppy, you have already got a DOS file
   system on it, you can use a command like this:

 # mount -t msdosfs /dev/fd0c /floppy

   if it is a floppy, or this:

 # mount -t msdosfs /dev/da2s4 /zip

   for a ZIP disk with the factory configuration.

   For other disks, see how they are laid out using fdisk(8) or
   sysinstall(8).

   The rest of the examples will be for a ZIP drive on da2, the third
   SCSI disk.

   Unless it is a floppy, or a removable you plan on sharing with
   other people, it is probably a better idea to stick a BSD file
   system on it. You will get long filename support, at least a 2X
   improvement in performance, and a lot more stability. First, you
   need to redo the DOS-level partitions/file systems. You can either
   use fdisk(8) or sysinstall(8), or for a small drive that you do
   not want to bother with multiple operating system support on, just
   blow away the whole FAT partition table (slices) and just use the
   BSD partitioning:

 # dd if=/dev/zero of=/dev/rda2 count=2
 # disklabel -Brw da2 auto

   You can use disklabel(8) or sysinstall(8) to create multiple BSD
   partitions. You will certainly want to do this if you are adding
   swap space on a fixed disk, but it is probably irrelevant on a
   removable drive like a ZIP.

   Finally, create a new file system, this one is on our ZIP drive
   using the whole disk:

 # newfs /dev/rda2c

   and mount it:

 # mount /dev/da2c /zip

   and it is probably a good idea to add a line like this to
   /etc/fstab (see fstab(5)) so you can just type mount /zip in the
   future:

 /dev/da2c /zip ffs rw,noauto 0 0

   9.16. Why do I get "Incorrect super block" when mounting a CD-ROM?

   You have to tell mount(8) the type of the device that you want to
   mount. This is described in the Handbook section on optical media,
   specifically the section Using Data CDs.

   9.17. Why do I get "Device not configured" when mounting a CD-ROM?

   This generally means that there is no CD-ROM in the CD-ROM drive,
   or the drive is not visible on the bus. Please see the Using Data
   CDs section of the Handbook for a detailed discussion of this
   issue.

   9.18. Why do all non-English characters in filenames show up as
   "?" on my CDs when mounted in FreeBSD?

   Your CD-ROM probably uses the "Joliet" extension for storing
   information about files and directories. This is discussed in the
   Handbook chapter on creating and using CD-ROMs, specifically the
   section on Using Data CD-ROMs.

   9.19. I burned a CD under FreeBSD and now I can not read it under
   any other operating system. Why?

   You most likely burned a raw file to your CD, rather than creating
   an ISO 9660 file system. Take a look at the Handbook chapter on
   creating CD-ROMs, particularly the section on burning raw data
   CDs.

   9.20. How can I create an image of a data CD?

   This is discussed in the Handbook section on duplicating data CDs.
   For more on working with CD-ROMs, see the Creating CDs Section in
   the Storage chapter in the Handbook.

   9.21. Why can I not mount an audio CD?

   If you try to mount an audio CD, you will get an error like
   "cd9660: /dev/acd0c: Invalid argument". This is because mount only
   works on file systems. Audio CDs do not have file systems; they
   just have data. You need a program that reads audio CDs, such as
   the audio/xmcd port.

   9.22. How do I mount a multi-session CD?

   By default, mount(8) will attempt to mount the last data track
   (session) of a CD. If you would like to load an earlier session,
   you must use the -s command line argument. Please see
   mount_cd9660(8) for specific examples.

   9.23. How do I let ordinary users mount floppies, CD-ROMs and
   other removable media?

   Ordinary users can be permitted to mount devices. Here is how:

    1. As root set the sysctl variable vfs.usermount to 1.

 # sysctl -w vfs.usermount=1

    2. As root assign the appropriate permissions to the block device
       associated with the removable media.

       For example, to allow users to mount the first floppy drive,
       use:

 # chmod 666 /dev/fd0

       To allow users in the group operator to mount the CD-ROM
       drive, use:

 # chgrp operator /dev/acd0c
 # chmod 640 /dev/acd0c

    3. You will need to alter /etc/devfs.conf to make these changes
       permanent across reboots.

       As root, add the necessary lines to /etc/devfs.conf. For
       example, to allow users to mount the first floppy drive add:

 # Allow all users to mount the floppy disk.
 own       /dev/fd0        root:operator
 perm      /dev/fd0        0666

       To allow users in the group operator to mount the CD-ROM drive
       add:

 # Allow members of the group operator to mount CD-ROMs.
 own       /dev/acd0       root:operator
 perm      /dev/acd0       0660

    4. Finally, add the line vfs.usermount=1 to the file
       /etc/sysctl.conf so that it is reset at system boot time.

   All users can now mount the floppy /dev/fd0 onto a directory that
   they own:

 % mkdir ~/my-mount-point
 % mount -t msdosfs /dev/fd0 ~/my-mount-point

   Users in group operator can now mount the CD-ROM /dev/acd0c onto a
   directory that they own:

 % mkdir ~/my-mount-point
 % mount -t cd9660 /dev/acd0c ~/my-mount-point

   Unmounting the device is simple:

 % umount ~/my-mount-point

   Enabling vfs.usermount, however, has negative security
   implications. A better way to access MS-DOS formatted media is to
   use the emulators/mtools package in the Ports Collection.

     Note: The device name used in the previous examples must be
     changed according to your configuration.

   9.24. The du and df commands show different amounts of disk space
   available. What is going on?

   You need to understand what du and df really do. du goes through
   the directory tree, measures how large each file is, and presents
   the totals. df just asks the file system how much space it has
   left. They seem to be the same thing, but a file without a
   directory entry will affect df but not du.

   When a program is using a file, and you delete the file, the file
   is not really removed from the file system until the program stops
   using it. The file is immediately deleted from the directory
   listing, however. You can see this easily enough with a program
   such as more. Assume you have a file large enough that its
   presence affects the output of du and df. (Since disks can be so
   large today, this might be a very large file!) If you delete this
   file while using more on it, more does not immediately choke and
   complain that it cannot view the file. The entry is simply removed
   from the directory so no other program or user can access it. du
   shows that it is gone -- it has walked the directory tree and the
   file is not listed. df shows that it is still there, as the file
   system knows that more is still using that space. Once you end the
   more session, du and df will agree.

   Note that Soft Updates can delay the freeing of disk space; you
   might need to wait up to 30 seconds for the change to be visible!

   This situation is common on web servers. Many people set up a
   FreeBSD web server and forget to rotate the log files. The access
   log fills up /var. The new administrator deletes the file, but the
   system still complains that the partition is full. Stopping and
   restarting the web server program would free the file, allowing
   the system to release the disk space. To prevent this from
   happening, set up newsyslog(8).

   9.25. How can I add more swap space?

   In the Configuration and Tuning section of the Handbook, you will
   find a section describing how to do this.

   9.26. Why does FreeBSD see my disk as smaller than the
   manufacturer says it is?

   Disk manufacturers calculate gigabytes as a billion bytes each,
   whereas FreeBSD calculates them as 1,073,741,824 bytes each. This
   explains why, for example, FreeBSD's boot messages will report a
   disk that supposedly has 80 GB as holding 76,319 MB.

   Also note that FreeBSD will (by default) reserve 8% of the disk
   space.

   9.27. How is it possible for a partition to be more than 100%
   full?

   A portion of each UFS partition (8%, by default) is reserved for
   use by the operating system and the root user. df(1) does not
   count that space when calculating the Capacity column, so it can
   exceed 100%. Also, you will notice that the Blocks column is
   always greater than the sum of the Used and Avail columns, usually
   by a factor of 8%.

   For more details, look up the -m option in tunefs(8).

     --------------------------------------------------------------

                    Chapter 10 System Administration

   10.1. Where are the system start-up configuration files?

   10.2. How do I add a user easily?

   10.3. Why do I keep getting messages like "root: not found" after
   editing my crontab file?

   10.4. Why do I get the error, "you are not in the correct group to
   su root" when I try to su to root?

   10.5. I made a mistake in rc.conf, or another startup file, and
   now I cannot edit it because the file system is read-only. What
   should I do?

   10.6. Why am I having trouble setting up my printer?

   10.7. How can I correct the keyboard mappings for my system?

   10.8. Why do I get messages like: "unknown: <PNP0303> can't assign
   resources" on boot?

   10.9. Why can I not get user quotas to work properly?

   10.10. Does FreeBSD support System V IPC primitives?

   10.11. What other mail-server software can I use instead of
   sendmail?

   10.12. I have forgotten the root password! What do I do?

   10.13. How do I keep Control+Alt+Delete from rebooting the system?

   10.14. How do I reformat DOS text files to UNIX ones?

   10.15. How do I kill processes by name?

   10.16. Why is su(1) bugging me about not being in root's ACL?

   10.17. How do I uninstall Kerberos?

   10.18. What happened to /dev/MAKEDEV?

   10.19. How do I add pseudoterminals to the system?

   10.20. How do I re-read /etc/rc.conf and re-start /etc/rc without
   a reboot?

   10.21. I tried to update my system to the latest -STABLE, but got
   -BETAx, -RC or -PRERELEASE! What is going on?

   10.22. I tried to install a new kernel, and the chflags(1) failed.
   How do I get around this?

   10.23. I cannot change the time on my system by more than one
   second! How do I get around this?

   10.24. Why is rpc.statd using 256 MB of memory?

   10.25. Why can I not unset the schg file flag?

   10.26. Why does SSH authentication through .shosts not work by
   default in recent versions of FreeBSD?

   10.27. What is vnlru?

   10.28. What do the various memory states displayed by top mean?

   10.29. How much free memory is available?

   10.30. What is /var/empty? I can not delete it!

   10.1. Where are the system start-up configuration files?

   The primary configuration file is /etc/defaults/rc.conf (see
   rc.conf(5)). System startup scripts such as /etc/rc and /etc/rc.d
   (see rc(8)) just include this file. Do not edit this file!
   Instead, if there is any entry in /etc/defaults/rc.conf that you
   want to change, you should copy the line into /etc/rc.conf and
   change it there.

   For example, if you wish to start named(8), the included DNS
   server, all you need to do is:

 # echo named_enable="YES" >> /etc/rc.conf

   To start up local services, place shell scripts in the
   /usr/local/etc/rc.d directory. These shell scripts should be set
   executable, the default file mode is 555.

   10.2. How do I add a user easily?

   Use the adduser(8) command, or the pw(8) command for more
   complicated situations.

   To remove the user, use the rmuser(8) command or, if necessary,
   pw(8).

   10.3. Why do I keep getting messages like "root: not found" after
   editing my crontab file?

   This is normally caused by editing the system crontab
   (/etc/crontab) and then using crontab(1) to install it:

 # crontab /etc/crontab

   This is not the correct way to do things. The system crontab has a
   different format to the per-user crontabs which crontab(1) updates
   (the crontab(5) manual page explains the differences in more
   detail).

   If this is what you did, the extra crontab is simply a copy of
   /etc/crontab in the wrong format it. Delete it with the command:

 # crontab -r

   Next time, when you edit /etc/crontab, you should not do anything
   to inform cron(8) of the changes, since it will notice them
   automatically.

   If you want something to be run once per day, week, or month, it
   is probably better to add shell scripts /usr/local/etc/periodic,
   and let the periodic(8) command run from the system cron schedule
   it with the other periodic system tasks.

   The actual reason for the error is that the system crontab has an
   extra field, specifying which user to run the command as. In the
   default system crontab provided with FreeBSD, this is root for all
   entries. When this crontab is used as the root user's crontab
   (which is not the same as the system crontab), cron(8) assumes the
   string root is the first word of the command to execute, but no
   such command exists.

   10.4. Why do I get the error, "you are not in the correct group to
   su root" when I try to su to root?

   This is a security feature. In order to su to root (or any other
   account with superuser privileges), you must be in the wheel
   group. If this feature were not there, anybody with an account on
   a system who also found out root's password would be able to gain
   superuser level access to the system. With this feature, this is
   not strictly true; su(1) will prevent them from even trying to
   enter the password if they are not in wheel.

   To allow someone to su to root, simply put them in the wheel
   group.

   10.5. I made a mistake in rc.conf, or another startup file, and
   now I cannot edit it because the file system is read-only. What
   should I do?

   Restart the system using boot -s at the loader prompt to enter
   Single User mode. When prompted for a shell pathname, simply press
   Enter, and run mount -urw / to re-mount the root file system in
   read/write mode. You may also need to run mount -a -t ufs to mount
   the file system where your favorite editor is defined. If your
   favorite editor is on a network file system, you will need to
   either configure the network manually before you can mount network
   file systems, or use an editor which resides on a local file
   system, such as ed(1).

   If you intend to use a full screen editor such as vi(1) or
   emacs(1), you may also need to run export TERM=cons25 so that
   these editors can load the correct data from the termcap(5)
   database.

   Once you have performed these steps, you can edit /etc/rc.conf as
   you usually would to fix the syntax error. The error message
   displayed immediately after the kernel boot messages should tell
   you the number of the line in the file which is at fault.

   10.6. Why am I having trouble setting up my printer?

   See the Handbook entry on printing. It should cover most of your
   problem.

   Some printers require a host-based driver to do any kind of
   printing. These so-called "WinPrinters" are not natively supported
   by FreeBSD. If your printer does not work in DOS or Windows, it is
   probably a WinPrinter. Your only hope of getting one of these to
   work is to check if the print/pnm2ppa port supports it.

   10.7. How can I correct the keyboard mappings for my system?

   Please see the Handbook section on using localization,
   specifically the section on console setup.

   10.8. Why do I get messages like: "unknown: <PNP0303> can't assign
   resources" on boot?

   The following is an excerpt from a post to the FreeBSD-CURRENT
   mailing list.

     The "can't assign resources" messages indicate that the          
     devices are legacy ISA devices for which a non-PnP-aware       
     driver is compiled into the kernel. These include devices such 
     as keyboard controllers, the programmable interrupt controller 
     chip, and several other bits of standard infrastructure. The   
     resources cannot be assigned because there is already a driver 
     using those addresses.                                         
             --Garrett Wollman <wollman@FreeBSD.org>, 24 April 2001   

   10.9. Why can I not get user quotas to work properly?

   * It is possible that your kernel is not configured to use quotas.
     If this is the case, you will need to add the following line to
     your kernel configuration file and recompile:

 options QUOTA

     Please read the Handbook entry on quotas for full details.

   * Do not turn on quotas on /.

   * Put the quota file on the file system that the quotas are to be
     enforced on, i.e.:

            File System                  Quota file            
     /usr                      /usr/admin/quotas               
     /home                     /home/admin/quotas              
     ...                       ...                             

   10.10. Does FreeBSD support System V IPC primitives?

   Yes, FreeBSD supports System V-style IPC, including shared memory,
   messages and semaphores, in the GENERIC kernel. In a custom
   kernel, enable this support by adding the following lines to your
   kernel config.

 options    SYSVSHM          # enable shared memory
 options    SYSVSEM          # enable for semaphores
 options    SYSVMSG          # enable for messaging

   Recompile and install your kernel.

   10.11. What other mail-server software can I use instead of
   sendmail?

   The sendmail server is the default mail-server software for
   FreeBSD, but you can easily replace it with one of the other MTA
   (for instance, an MTA installed from the ports).

   There are various alternative MTAs in the ports tree already, with
   mail/exim, mail/postfix, mail/qmail, and mail/zmailer being some
   of the most popular choices.

   Diversity is nice, and the fact that you have many different
   mail-servers to chose from is considered a good thing; therefore
   try to avoid asking questions like "Is sendmail better than
   qmail?" in the mailing lists. If you do feel like asking, first
   check the mailing list archives. The advantages and disadvantages
   of each and every one of the available MTAs have already been
   discussed a few times.

   10.12. I have forgotten the root password! What do I do?

   Do not panic! Restart the system, type boot -s at the Boot: prompt
   to enter Single User mode. At the question about the shell to use,
   hit Enter. You will be dropped to a # prompt. Enter mount -urw /
   to remount your root file system read/write, then run mount -a to
   remount all the file systems. Run passwd root to change the root
   password then run exit(1) to continue booting.

     Note: If you are still prompted to give the root password when
     entering the Single User mode, it means that the console has
     been marked as insecure in /etc/ttys. In this case it will be
     required to boot from an FreeBSD installation disk, choose the
     Fixit shell from sysinstall(8) and issue the commands mentioned
     above.

     Note: If you cannot mount your root partition from Single User
     mode, it is possible that the partitions are encrypted and it is
     impossible to mount them without the access keys. Your chances
     are depending on the chosen implementation. For more information
     see the section about encrypted disks in the FreeBSD Handbook.

   10.13. How do I keep Control+Alt+Delete from rebooting the system?

   If you are using syscons(4) (the default console driver) build and
   install a new kernel with the line in the configuration file:

 options SC_DISABLE_REBOOT

   This can also be done by setting the following sysctl(8) which
   does not require a reboot or kernel recompile:

 # sysctl hw.syscons.kbd_reboot=0

     Note: The above two methods are exclusive: The sysctl(8) does
     not exist if you compile your kernel with the SC_DISABLE_REBOOT
     option.

   If you use the pcvt(4) console driver, use the following kernel
   configuration line instead and rebuild the kernel:

 options PCVT_CTRL_ALT_DEL

   10.14. How do I reformat DOS text files to UNIX ones?

   Use this perl(1) command:

 % perl -i.bak -npe 's/\r\n/\n/g' file(s)

   where file(s) is one or more files to process. The modification is
   done in-place, with the original file stored with a .bak
   extension.

   Alternatively you can use the tr(1) command:

 % tr -d '\r' < dos-text-file > unix-file

   dos-text-file is the file containing DOS text while unix-file will
   contain the converted output. This can be quite a bit faster than
   using perl.

   Yet another way to reformat DOS text files is to use the
   converters/dosunix port from the Ports Collection. Consult its
   documentation about the details.

   10.15. How do I kill processes by name?

   Use killall(1).

   10.16. Why is su(1) bugging me about not being in root's ACL?

   The error comes from the Kerberos distributed authentication
   system. The problem is not fatal but annoying. You can either run
   su with the -K option, or uninstall Kerberos as described in the
   next question.

   10.17. How do I uninstall Kerberos?

   To remove Kerberos from the system, reinstall the base
   distribution for the release you are running. If you have the
   CD-ROM, you can mount it (we will assume on /cdrom) and run the
   commands below:

 # cd /cdrom/base
 # ./install.sh

   Alternately, you can include the NO_KERBEROS option in your
   /etc/make.conf and rebuild world.

   10.18. What happened to /dev/MAKEDEV?

   FreeBSD 5.X and beyond use the devfs(8) device-on-demand system.
   Device drivers automatically create new device nodes as they are
   needed, obsoleting /dev/MAKEDEV.

   10.19. How do I add pseudoterminals to the system?

   If you have a lot of telnet, ssh, X, or screen users, you might
   run out of pseudoterminals. By default, FreeBSD 6.2 and earlier
   support 256 pseudoterminals, while FreeBSD 6.3 and later support
   512 pseudoterminals.

     Tip: If needed, more pseudoterminals can be added. However, this
     requires patching the standard C library, the kernel, and
     /etc/ttys. For example,
     http://www.freebsd.org/~jhb/patches/pty_1152.patch expands the
     number of pseudoterminals to 1152. Note that the patch will only
     apply cleanly to FreeBSD 6.3 or later.

   10.20. How do I re-read /etc/rc.conf and re-start /etc/rc without
   a reboot?

   Go into single user mode and then back to multi user mode.

   On the console do:

 # shutdown now
 (Note: without -r or -h)

 # return
 # exit

   10.21. I tried to update my system to the latest -STABLE, but got
   -BETAx, -RC or -PRERELEASE! What is going on?

   Short answer: it is just a name. RC stands for "Release
   Candidate". It signifies that a release is imminent. In FreeBSD,
   -PRERELEASE is typically synonymous with the code freeze before a
   release. (For some releases, the -BETA label was used in the same
   way as -PRERELEASE.)

   Long answer: FreeBSD derives its releases from one of two places.
   Major, dot-zero, releases, such as 6.0-RELEASE and 7.0-RELEASE,
   are branched from the head of the development stream, commonly
   referred to as -CURRENT. Minor releases, such as 6.3-RELEASE or
   5.2-RELEASE, have been snapshots of the active -STABLE branch.
   Starting with 4.3-RELEASE, each release also now has its own
   branch which can be tracked by people requiring an extremely
   conservative rate of development (typically only security
   advisories).

   When a release is about to be made, the branch from which it will
   be derived from has to undergo a certain process. Part of this
   process is a code freeze. When a code freeze is initiated, the
   name of the branch is changed to reflect that it is about to
   become a release. For example, if the branch used to be called
   6.2-STABLE, its name will be changed to 6.3-PRERELEASE to signify
   the code freeze and signify that extra pre-release testing should
   be happening. Bug fixes can still be committed to be part of the
   release. When the source code is in shape for the release the name
   will be changed to 6.3-RC to signify that a release is about to be
   made from it. Once in the RC stage, only the most critical bugs
   found can be fixed. Once the release (6.3-RELEASE in this example)
   and release branch have been made, the branch will be renamed to
   6.3-STABLE.

   For more information on version numbers and the various CVS
   branches, refer to the Release Engineering article.

   10.22. I tried to install a new kernel, and the chflags(1) failed.
   How do I get around this?

   Short answer: You are probably at security level greater than 0.
   Reboot directly to Single User mode to install the kernel.

   Long answer: FreeBSD disallows changing system flags at security
   levels greater than 0. You can check your security level with the
   command:

 # sysctl kern.securelevel

   You cannot lower the security level; you have to boot to Single
   Mode to install the kernel, or change the security level in
   /etc/rc.conf then reboot. See the init(8) manual page for details
   on securelevel, and see /etc/defaults/rc.conf and the rc.conf(5)
   manual page for more information on rc.conf.

   10.23. I cannot change the time on my system by more than one
   second! How do I get around this?

   Short answer: You are probably at security level greater than 1.
   Reboot directly to Single User mode to change the date.

   Long answer: FreeBSD disallows changing the time by more that one
   second at security levels greater than 1. You can check your
   security level with the command:

 # sysctl kern.securelevel

   You cannot lower the security level; you have to boot to Single
   User mode to change the date, or change the security level in
   /etc/rc.conf then reboot. See the init(8) manual page for details
   on securelevel, and see /etc/defaults/rc.conf and the rc.conf(5)
   manual page for more information on rc.conf.

   10.24. Why is rpc.statd using 256 MB of memory?

   No, there is no memory leak, and it is not using 256 MB of memory.
   For convenience, rpc.statd maps an obscene amount of memory into
   its address space. There is nothing terribly wrong with this from
   a technical standpoint; it just throws off things like top(1) and
   ps(1).

   rpc.statd(8) maps its status file (resident on /var) into its
   address space; to save worrying about remapping it later when it
   needs to grow, it maps it with a generous size. This is very
   evident from the source code, where one can see that the length
   argument to mmap(2) is 0x10000000, or one sixteenth of the address
   space on an IA32, or exactly 256 MB.

   10.25. Why can I not unset the schg file flag?

   You are running at an elevated (i.e., greater than 0) securelevel.
   Lower the securelevel and try again. For more information, see the
   FAQ entry on securelevel and the init(8) manual page.

   10.26. Why does SSH authentication through .shosts not work by
   default in recent versions of FreeBSD?

   The reason why .shosts authentication does not work by default in
   more recent versions of FreeBSD is because ssh(1) is not installed
   suid root by default. To "fix" this, you can do one of the
   following:

     * As a permanent fix, set ENABLE_SUID_SSH to true in
       /etc/make.conf then rebuild and install ssh(1) (or run make
       world).

     * As a temporary fix, change the mode on /usr/bin/ssh to 4555 by
       running chmod 4555 /usr/bin/ssh as root. Then add
       ENABLE_SUID_SSH= true to /etc/make.conf so the change takes
       effect the next time make world is run.

   10.27. What is vnlru?

   vnlru flushes and frees vnodes when the system hits the
   kern.maxvnodes limit. This kernel thread sits mostly idle, and
   only activates if you have a huge amount of RAM and are accessing
   tens of thousands of tiny files.

   10.28. What do the various memory states displayed by top mean?

   * Active: pages recently statistically used.

   * Inactive: pages recently statistically unused.

   * Cache: (most often) pages that have percolated from inactive to
     a status where they maintain their data, but can often be
     immediately reused (either with their old association, or reused
     with a new association). There can be certain immediate
     transitions from active to cache state if the page is known to
     be clean (unmodified), but that transition is a matter of
     policy, depending upon the algorithm choice of the VM system
     maintainer.

   * Free: pages without data content, and can be immediately used in
     certain circumstances where cache pages might be ineligible.
     Free pages can be reused at interrupt or process state.

   * Wired: pages that are fixed into memory, usually for kernel
     purposes, but also sometimes for special use in processes.

   Pages are most often written to disk (sort of a VM sync) when they
   are in the inactive state, but active pages can also be synced.
   This depends upon the CPU tracking of the modified bit being
   available, and in certain situations there can be an advantage for
   a block of VM pages to be synced, whether they are active or
   inactive. In most common cases, it is best to think of the
   inactive queue to be a queue of relatively unused pages that might
   or might not be in the process of being written to disk. Cached
   pages are already synced, not mapped, but available for immediate
   process use with their old association or with a new association.
   Free pages are available at interrupt level, but cached or free
   pages can be used at process state for reuse. Cache pages are not
   adequately locked to be available at interrupt level.

   There are some other flags (e.g., busy flag or busy count) that
   might modify some of the described rules.

   10.29. How much free memory is available?

   There are a couple of kinds of "free memory". One kind is the
   amount of memory immediately available without paging anything
   else out. That is approximately the size of cache queue + size of
   free queue (with a derating factor, depending upon system tuning).
   Another kind of "free memory" is the total amount of VM space.
   That can be complex, but is dependent upon the amount of swap
   space and memory. Other kinds of "free memory" descriptions are
   also possible, but it is relatively useless to define these, but
   rather it is important to make sure that the paging rate is kept
   low, and to avoid running out of swap space.

   10.30. What is /var/empty? I can not delete it!

   /var/empty is a directory that the sshd(8) program uses when
   performing privilege separation. The /var/empty directory is
   empty, owned by root and has the schg flag set.

   Although it is not recommended to delete this directory, to do so
   you will need to unset the schg flag first. See the chflags(1)
   manual page for more information (and bear in mind the answer to
   the question on unsetting the schg flag).

     --------------------------------------------------------------

          Chapter 11 The X Window System and Virtual Consoles

   11.1. What is the X Window System?

   11.2. Which X implementations are available for FreeBSD?

   11.3. Why did the X projects split, anyway?

   11.4. Why did FreeBSD choose to go with the Xorg ports by default?

   11.5. I want to run X, how do I go about it?

   11.6. I tried to run X, but I get an "KDENABIO failed (Operation
   not permitted)" error when I type startx. What do I do now?

   11.7. Why does my mouse not work with X?

   11.8. My mouse has a fancy wheel. Can I use it in X?

   11.9. How do I use remote X displays?

   11.10. What is a virtual console and how do I make more?

   11.11. How do I access the virtual consoles from X?

   11.12. How do I start XDM on boot?

   11.13. Why do I get "Couldn't open console" when I run xconsole?

   11.14. Before, I was able to run XFree86 as a regular user. Why
   does it now say that I must be root?

   11.15. Why does my PS/2 mouse misbehave under X?

   11.16. Why does my PS/2 mouse from MouseSystems not work?

   11.17. How do I reverse the mouse buttons?

   11.18. How do I install a splash screen and where do I find them?

   11.19. Can I use the Windows keys on my keyboard in X?

   11.20. How can I get 3D hardware acceleration for OpenGL(R)?

   11.1. What is the X Window System?

   The X Window System (commonly X11) is the most widely available
   windowing system capable of running on UNIX or UNIX like systems,
   including FreeBSD. The X.Org Foundation administers the X protocol
   standards, with the current reference implementation, version 11
   release 7.4, so you will often see references shortened to X11.

   Many implementations are available for different architectures and
   operating systems. An implementation of the server-side code is
   properly known as an X server.

   11.2. Which X implementations are available for FreeBSD?

   Historically, the default implementation of X on FreeBSD has been
   XFree86(TM) which is maintained by The XFree86 Project, Inc. This
   software was installed by default on FreeBSD versions up until
   4.10 and 5.2. Although Xorg itself maintained an implementation
   during that time period, it was basically only provided as a
   reference platform, as it had suffered greatly from bitrot over
   the years.

   However, early in 2004, some XFree86 developers left that project
   over issues including the pace of code changes, future directions,
   and interpersonal conflicts, and are now contributing code
   directly to Xorg instead. At that time, Xorg updated its source
   tree to the last XFree86 release before its subsequent licensing
   change (XFree86 version 4.3.99.903), incorporated many changes
   that had previously been maintained separately, and has released
   that software as X11R6.7.0. A separate but related project,
   freedesktop.org (or fd.o for short), is working on rearchitecting
   the original XFree86 code to offload more work onto the graphics
   cards (with the goal of increased performance) and make it more
   modular (with the goal of increased maintainability, and thus
   faster releases as well as easier configuration). Xorg intends to
   incorporate the freedesktop.org changes in its future releases.

   As of July 2004, in FreeBSD-CURRENT, XFree86 has been replaced
   with Xorg as the default implementation. Since then the default
   X11 implementation in FreeBSD is Xorg.

   For further information, read the X11 section of the FreeBSD
   Handbook.

   11.3. Why did the X projects split, anyway?

   The answer to this question is outside the scope of this FAQ. Note
   that there are voluminous postings in various mailing list
   archives on the Internet; please use your favorite search engine
   to investigate the history instead of asking this question on the
   FreeBSD mailing lists. It may even be the case that only the
   participants will ever know for certain.

   11.4. Why did FreeBSD choose to go with the Xorg ports by default?

   The Xorg developers claimed that their goal is to release more
   often and incorporate new features more quickly. If they are able
   to do so, this will be very attractive. Also, their software still
   uses the traditional X license, while XFree86 is using their
   modified one.

   11.5. I want to run X, how do I go about it?

   If you would like to add X to an existing installation, you should
   use either the x11/xorg meta-port, which will build and install
   all the necessary components, or install Xorg from FreeBSD
   packages:

 # pkg_add -r xorg

   It is also possible to install Xorg from sysinstall(8) by choosing
   Configure, then Distributions, then The X.Org Distribution.

   After the installation of Xorg was successful, follow the
   instructions from xorgconfig(1). It will assists you in
   configuring Xorg for your particular graphics card/mouse/etc. You
   may also wish to examine the xorgcfg(1) tool, which provides a
   graphical interface to the X configuration process.

   For further information, read the X11 section of the FreeBSD
   Handbook.

   11.6. I tried to run X, but I get an "KDENABIO failed (Operation
   not permitted)" error when I type startx. What do I do now?

   Your system is probably running at a raised securelevel. It is not
   possible to start X at a raised securelevel because X requires
   write access to io(4). For more information, see at the init(8)
   manual page.

   So the question is what else you should do instead, and you
   basically have two choices: set your securelevel back down to zero
   (usually from /etc/rc.conf), or run xdm(1) at boot time (before
   the securelevel is raised).

   See Q: 11.12. for more information about running xdm(1) at boot
   time.

   11.7. Why does my mouse not work with X?

   If you are using syscons(4) (the default console driver), you can
   configure FreeBSD to support a mouse pointer on each virtual
   screen. In order to avoid conflicting with X, syscons(4) supports
   a virtual device called /dev/sysmouse. All mouse events received
   from the real mouse device are written to the sysmouse(4) device
   via moused(8). If you wish to use your mouse on one or more
   virtual consoles, and use X, see Q: 4.5.4. and set up moused.

   Then edit /etc/X11/xorg.conf and make sure you have the following
   lines:

 Section "InputDevice"
    Option          "Protocol" "SysMouse"
    Option          "Device" "/dev/sysmouse"
 .....

   Some people prefer to use /dev/mouse under X. To make this work,
   /dev/mouse should be linked to /dev/sysmouse (see sysmouse(4)) by
   adding the following line to /etc/devfs.conf (see devfs.conf(5)):

 link    sysmouse    mouse

   This link can be created by restarting devfs(5) with the following
   command (as root):

 # /etc/rc.d/devfs restart

   11.8. My mouse has a fancy wheel. Can I use it in X?

   Yes.

   You need to tell X that you have a 5 button mouse. To do this,
   simply add the lines Buttons 5 and ZAxisMapping 4 5 to the
   "InputDevice" section of /etc/X11/xorg.conf. For example, you
   might have the following "InputDevice" section in
   /etc/X11/xorg.conf.

   Example 11-1. "InputDevice" Section for Wheeled Mouse in Xorg
   Configuration File

 Section "InputDevice"
    Identifier      "Mouse1"
    Driver          "mouse"
    Option          "Protocol" "auto"
    Option          "Device" "/dev/sysmouse"
    Option          "Buttons" "5"
    Option          "ZAxisMapping" "4 5"
 EndSection

   Example 11-2. ".emacs" Example for Naive Page Scrolling with
   Wheeled Mouse (optional)

 ;; wheel mouse
 (global-set-key [mouse-4] 'scroll-down)
 (global-set-key [mouse-5] 'scroll-up)

   11.9. How do I use remote X displays?

   For security reasons, the default setting is to not allow a
   machine to remotely open a window.

   To enable this feature, simply start X with the optional
   -listen_tcp argument:

 % startx -listen_tcp

   11.10. What is a virtual console and how do I make more?

   Virtual consoles, put simply, enable you to have several
   simultaneous sessions on the same machine without doing anything
   complicated like setting up a network or running X.

   When the system starts, it will display a login prompt on the
   monitor after displaying all the boot messages. You can then type
   in your login name and password and start working (or playing!) on
   the first virtual console.

   At some point, you will probably wish to start another session,
   perhaps to look at documentation for a program you are running or
   to read your mail while waiting for an FTP transfer to finish.
   Just do Alt+F2 (hold down the Alt key and press the F2 key), and
   you will find a login prompt waiting for you on the second
   "virtual console"! When you want to go back to the original
   session, do Alt+F1.

   The default FreeBSD installation has eight virtual consoles
   enabled. Alt+F1, Alt+F2, Alt+F3, and so on will switch between
   these virtual consoles.

   To enable more of them, edit /etc/ttys (see ttys(5)) and add
   entries for ttyv8 to ttyvc after the comment on "Virtual
   terminals":

 # Edit the existing entry for ttyv8 in /etc/ttys and change
 # "off" to "on".
 ttyv8   "/usr/libexec/getty Pc"         cons25  on secure
 ttyv9   "/usr/libexec/getty Pc"         cons25  on secure
 ttyva   "/usr/libexec/getty Pc"         cons25  on secure
 ttyvb   "/usr/libexec/getty Pc"         cons25  on secure

   Use as many or as few as you want. The more virtual terminals you
   have, the more resources that are used; this can be important if
   you have 8 MB RAM or less. You may also want to change the secure
   to insecure.

     Important: If you want to run an X server you must leave at
     least one virtual terminal unused (or turned off) for it to use.
     That is to say that if you want to have a login prompt pop up
     for all twelve of your Alt-function keys, you are out of luck --
     you can only do this for eleven of them if you also want to run
     an X server on the same machine.

   The easiest way to disable a console is by turning it off. For
   example, if you had the full 12 terminal allocation mentioned
   above and you wanted to run X, you would change settings for
   virtual terminal 12 from:

 ttyvb   "/usr/libexec/getty Pc"         cons25  on  secure

   to:

 ttyvb   "/usr/libexec/getty Pc"         cons25  off secure

   If your keyboard has only ten function keys, you would end up
   with:

 ttyv9   "/usr/libexec/getty Pc"         cons25  off secure
 ttyva   "/usr/libexec/getty Pc"         cons25  off secure
 ttyvb   "/usr/libexec/getty Pc"         cons25  off secure

   (You could also just delete these lines.)

   Next, the easiest (and cleanest) way to activate the virtual
   consoles is to reboot. However, if you really do not want to
   reboot, you can just shut down the X Window system and execute (as
   root):

 # kill -HUP 1

   It is imperative that you completely shut down X Window if it is
   running, before running this command. If you do not, your system
   will probably appear to hang or lock up after executing the kill
   command.

   11.11. How do I access the virtual consoles from X?

   Use Ctrl+Alt+Fn to switch back to a virtual console. Ctrl+Alt+F1
   would return you to the first virtual console.

   Once you are back to a text console, you can then use Alt+Fn as
   normal to move between them.

   To return to the X session, you must switch to the virtual console
   running X. If you invoked X from the command line, (e.g., using
   startx) then the X session will attach to the next unused virtual
   console, not the text console from which it was invoked. If you
   have eight active virtual terminals then X will be running on the
   ninth, and you would use Alt+F9 to return.

   11.12. How do I start XDM on boot?

   There are two schools of thought on how to start xdm(1). One
   school starts xdm from /etc/ttys (see ttys(5)) using the supplied
   example, while the other simply runs xdm from from rc.local (see
   rc(8)) or from an X script in /usr/local/etc/rc.d. Both are
   equally valid, and one may work in situations where the other does
   not. In both cases the result is the same: X will pop up a
   graphical login prompt.

   The ttys(5) method has the advantage of documenting which vty X
   will start on and passing the responsibility of restarting the X
   server on logout to init(8). The rc(8) method makes it easy to
   kill xdm if there is a problem starting the X server.

   If loaded from rc(8), xdm should be started without any arguments
   (i.e., as a daemon). The xdm command must start after getty(8)
   runs, or else getty and xdm will conflict, locking out the
   console. The best way around this is to have the script sleep 10
   seconds or so then launch xdm.

   If you are to start xdm from /etc/ttys, there still is a chance of
   conflict between xdm and getty(8). One way to avoid this is to add
   the vt number in the /usr/local/lib/X11/xdm/Xservers file:

 :0 local /usr/local/bin/X vt4

   The above example will direct the X server to run in /dev/ttyv3.
   Note the number is offset by one. The X server counts the vty from
   one, whereas the FreeBSD kernel numbers the vty from zero.

   11.13. Why do I get "Couldn't open console" when I run xconsole?

   If you start X with startx, the permissions on /dev/console will
   not get changed, resulting in things like xterm -C and xconsole
   not working.

   This is because of the way console permissions are set by default.
   On a multi-user system, one does not necessarily want just any
   user to be able to write on the system console. For users who are
   logging directly onto a machine with a VTY, the fbtab(5) file
   exists to solve such problems.

   In a nutshell, make sure an uncommented line of the form is in
   /etc/fbtab (see fbtab(5)):

 /dev/ttyv0 0600 /dev/console

   It will ensure that whomever logs in on /dev/ttyv0 will own the
   console.

   11.14. Before, I was able to run XFree86 as a regular user. Why
   does it now say that I must be root?

   All X servers need to be run as root in order to get direct access
   to your video hardware. Older versions of XFree86 (<= 3.3.6)
   installed all bundled servers to be automatically run as root
   (setuid to root). This is obviously a security hazard because X
   servers are large, complicated programs. Newer versions of XFree86
   do not install the servers setuid to root for just this reason.

   Obviously, running an X server as the root user is not acceptable,
   nor a good idea security-wise. There are two ways to be able to
   use X as a regular user. The first is to use xdm or another
   display manager (e.g., kdm); the second is to use the Xwrapper.

   xdm is a daemon that handles graphical logins. It is usually
   started at boot time, and is responsible for authenticating users
   and starting their sessions; it is essentially the graphical
   counterpart of getty(8) and login(1). For more information on xdm
   see the XFree86 documentation, and the the FAQ entry on it.

   Xwrapper is the X server wrapper; it is a small utility to enable
   one to manually run an X server while maintaining reasonable
   safety. It performs some sanity checks on the command line
   arguments given, and if they pass, runs the appropriate X server.
   If you do not want to run a display manager for whatever reason,
   this is for you. If you have installed the complete Ports
   Collection, you can find the port in x11/wrapper.

   11.15. Why does my PS/2 mouse misbehave under X?

   Your mouse and the mouse driver may have somewhat become out of
   synchronization.

   In rare cases the driver may erroneously report synchronization
   problem and you may see the kernel message:

 psmintr: out of sync (xxxx != yyyy)

   and notice that your mouse does not work properly.

   If this happens, disable the synchronization check code by setting
   the driver flags for the PS/2 mouse driver to 0x100. Enter
   UserConfig by giving the -c option at the boot prompt:

 boot: -c

   Then, in the UserConfig command line, type:

 UserConfig> flags psm0 0x100
 UserConfig> quit

   11.16. Why does my PS/2 mouse from MouseSystems not work?

   There have been some reports that certain model of PS/2 mouse from
   MouseSystems works only if it is put into the "high resolution"
   mode. Otherwise, the mouse cursor may jump to the upper-left
   corner of the screen every so often.

   Specify the flags 0x04 to the PS/2 mouse driver to put the mouse
   into the high resolution mode. Enter UserConfig by giving the -c
   option at the boot prompt:

 boot: -c

   Then, in the UserConfig command line, type:

 UserConfig> flags psm0 0x04
 UserConfig> quit

   See the previous section for another possible cause of mouse
   problems.

   11.17. How do I reverse the mouse buttons?

   Run the command xmodmap -e "pointer = 3 2 1" from your .xinitrc or
   .xsession.

   11.18. How do I install a splash screen and where do I find them?

   The detailed answer for this question can be found in the Boot
   Time Splash Screens section of the FreeBSD Handbook.

   11.19. Can I use the Windows keys on my keyboard in X?

   Yes. All you need to do is use xmodmap(1) to define what function
   you wish them to perform.

   Assuming all "Windows" keyboards are standard then the keycodes
   for these three keys are the following:

     * 115 -- Windows key, between the left-hand Ctrl and Alt keys

     * 116 -- Windows key, to the right of the AltGr key

     * 117 -- Menu key, to the left of the right-hand Ctrl key

   To have the left Windows key print a comma, try this.

 # xmodmap -e "keycode 115 = comma"

   You will probably have to re-start your window manager to see the
   result.

   To have the Windows key-mappings enabled automatically every time
   you start X either put the xmodmap commands in your ~/.xinitrc
   file or, preferably, create a file ~/.xmodmaprc and include the
   xmodmap options, one per line, then add the following line to your
   ~/.xinitrc:

 xmodmap $HOME/.xmodmaprc

   For example, you could map the 3 keys to be F13, F14, and F15,
   respectively. This would make it easy to map them to useful
   functions within applications or your window manager, as
   demonstrated further down.

   To do this put the following in ~/.xmodmaprc.

 keycode 115 = F13
 keycode 116 = F14
 keycode 117 = F15

   If you use the x11-wm/fvwm2 port, for example, you could map the
   keys so that F13 iconifies (or de-iconifies) the window the cursor
   is in, F14 brings the window the cursor is in to the front or, if
   it is already at the front, pushes it to the back, and F15 pops up
   the main Workplace (application) menu even if the cursor is not on
   the desktop, which is useful if you do not have any part of the
   desktop visible (and the logo on the key matches its
   functionality).

   The following entries in ~/.fvwmrc implement the aforementioned
   setup:

 Key F13        FTIWS    A        Iconify
 Key F14        FTIWS    A        RaiseLower
 Key F15        A        A        Menu Workplace Nop

   11.20. How can I get 3D hardware acceleration for OpenGL(R)?

   The availability of 3D acceleration depends on the version of Xorg
   that you are using and the type of video chip you have. If you
   have an nVidia chip, you can use the binary drivers provided for
   FreeBSD by installing one of the following ports:

     * The latest versions of nVidia cards are supported by the
       x11/nvidia-driver port.

     * nVidia cards like the GeForce2 MX/3/4 series are supported by
       the 96XX series of drivers, available in the
       x11/nvidia-driver-96xx port.

     * Even older cards, like GeForce and RIVA TNT are supported by
       the 71XX series of drivers, available in the
       x11/nvidia-driver-71xx port.

   In fact, nVidia provides detailed information on which card is
   supported by which driver. This information is available directly
   on their web site: http://www.nvidia.com/object/IO_32667.html.

   For Matrox G200/G400, you should check the x11-servers/mga_hal
   port.

   For ATI Rage 128 and Radeon, see the ati(4), r128(4) and radeon(4)
   manual pages.

   For 3dfx Voodoo 3, 4, 5, and Banshee cards, there is a
   x11-servers/driglide port.

     --------------------------------------------------------------

                         Chapter 12 Networking

   12.1. Where can I get information on "diskless booting"?

   12.2. Can a FreeBSD box be used as a dedicated network router?

   12.3. Can I connect my Windows box to the Internet via FreeBSD?

   12.4. Does FreeBSD support SLIP and PPP?

   12.5. Does FreeBSD support NAT or Masquerading?

   12.6. How do I connect two FreeBSD systems over a parallel line
   using PLIP?

   12.7. How can I set up Ethernet aliases?

   12.8. How do I get my 3C503 to use the other network port?

   12.9. Why am I having trouble with NFS and FreeBSD?

   12.10. Why can I not NFS-mount from a Linux box?

   12.11. Why can I not NFS-mount from a Sun box?

   12.12. Why does mountd keep telling me it "can't change
   attributes" and that I have a "bad exports list" on my FreeBSD NFS
   server?

   12.13. Why am I having problems talking PPP to NeXTStep machines?

   12.14. How do I enable IP multicast support?

   12.15. Which network cards are based on the DEC PCI chipset?

   12.16. Why do I have to use the FQDN for hosts on my site?

   12.17. Why do I get an error, "Permission denied", for all
   networking operations?

   12.18. Why is my ipfw "fwd" rule to redirect a service to another
   machine not working?

   12.19. How can I redirect service requests from one machine to
   another?

   12.20. Where can I get a bandwidth management tool?

   12.21. Why do I get "/dev/bpf0: device not configured"?

   12.22. How do I mount a disk from a Windows machine that is on my
   network, like smbmount in Linux?

   12.23. What are these messages about: "Limiting icmp/open
   port/closed port response" in my log files?

   12.24. What are these "arp: unknown hardware address format" error
   messages?

   12.25. Why do I keep seeing messages like: "192.168.0.10 is on
   fxp1 but got reply from 00:15:17:67:cf:82 on rl0", and how do I
   disable it?

   12.26. I have just installed CVSup but trying to execute it
   produces errors. What is wrong?

   12.1. Where can I get information on "diskless booting"?

   "Diskless booting" means that the FreeBSD box is booted over a
   network, and reads the necessary files from a server instead of
   its hard disk. For full details, please read the Handbook entry on
   diskless booting

   12.2. Can a FreeBSD box be used as a dedicated network router?

   Yes. Please see the Handbook entry on advanced networking,
   specifically the section on routing and gateways.

   12.3. Can I connect my Windows box to the Internet via FreeBSD?

   Typically, people who ask this question have two PCs at home, one
   with FreeBSD and one with some version of Windows the idea is to
   use the FreeBSD box to connect to the Internet and then be able to
   access the Internet from the Windows box through the FreeBSD box.
   This is really just a special case of the previous question and
   works perfectly well.

   If you are using dialup to connect to the Internet user-mode
   ppp(8) contains a -nat option. If you run ppp(8) with the -nat
   option, set gateway_enable to YES in /etc/rc.conf, and configure
   your Windows machine correctly, this should work fine. For more
   information, please see the ppp(8) manual page or the Handbook
   entry on user PPP.

   If you are using kernel-mode PPP or have an Ethernet connection to
   the Internet, you need to use natd(8). Please look at the natd
   section of the Handbook for a tutorial.

   12.4. Does FreeBSD support SLIP and PPP?

   Yes. See the manual pages for slattach(8), sliplogin(8), ppp(8),
   and pppd(8). ppp(8) and pppd(8) provide support for both incoming
   and outgoing connections, while sliplogin(8) deals exclusively
   with incoming connections, and slattach(8) deals exclusively with
   outgoing connections.

   For more information on how to use these, please see the Handbook
   chapter on PPP and SLIP.

   If you only have access to the Internet through a "shell account",
   you may want to have a look at the net/slirp package. It can
   provide you with (limited) access to services such as ftp and http
   direct from your local machine.

   12.5. Does FreeBSD support NAT or Masquerading?

   Yes. If you want to use NAT over a user PPP connection, please see
   the Handbook entry on user PPP. If you want to use NAT over some
   other sort of network connection, please look at the natd section
   of the Handbook.

   12.6. How do I connect two FreeBSD systems over a parallel line
   using PLIP?

   Please see the PLIP section of the Handbook.

   12.7. How can I set up Ethernet aliases?

   If the alias is on the same subnet as an address already
   configured on the interface, then add netmask 0xffffffff to your
   ifconfig(8) command-line, as in the following:

 # ifconfig ed0 alias 192.0.2.2 netmask 0xffffffff

   Otherwise, just specify the network address and netmask as usual:

 # ifconfig ed0 alias 172.16.141.5 netmask 0xffffff00

   You can read more about this in the FreeBSD Handbook.

   12.8. How do I get my 3C503 to use the other network port?

   If you want to use the other ports, you will have to specify an
   additional parameter on the ifconfig(8) command line. The default
   port is link0. To use the AUI port instead of the BNC one, use
   link2. These flags should be specified using the ifconfig_*
   variables in /etc/rc.conf (see rc.conf(5)).

   12.9. Why am I having trouble with NFS and FreeBSD?

   Certain PC network cards are better than others (to put it mildly)
   and can sometimes cause problems with network intensive
   applications like NFS.

   See the Handbook entry on NFS for more information on this topic.

   12.10. Why can I not NFS-mount from a Linux box?

   Some versions of the Linux NFS code only accept mount requests
   from a privileged port; try to issue the following command:

 # mount -o -P linuxbox:/blah /mnt

   12.11. Why can I not NFS-mount from a Sun box?

   Sun workstations running SunOS(TM) 4.X only accept mount requests
   from a privileged port; try the following command:

 # mount -o -P sunbox:/blah /mnt

   12.12. Why does mountd keep telling me it "can't change
   attributes" and that I have a "bad exports list" on my FreeBSD NFS
   server?

   The most frequent problem is not understanding the correct format
   of /etc/exports. Please review exports(5) and the NFS entry in the
   Handbook, especially the section on configuring NFS.

   12.13. Why am I having problems talking PPP to NeXTStep machines?

   Try disabling the TCP extensions in /etc/rc.conf (see rc.conf(5))
   by changing the following variable to NO:

 tcp_extensions=NO

   Xylogic's Annex boxes are also broken in this regard and you must
   use the above change to connect through them.

   12.14. How do I enable IP multicast support?

   FreeBSD supports multicast host operations by default. If you want
   your box to run as a multicast router, you need to recompile your
   kernel with the MROUTING option and run mrouted(8). FreeBSD will
   start mrouted(8) at boot time if the flag mrouted_enable is set to
   YES in /etc/rc.conf.

     Note: In recent FreeBSD releases, the mrouted(8) multicast
     routing daemon, the map-mbone(8) and mrinfo(8) utilities have
     been removed from the base system. These programs are now
     available in the FreeBSD Ports Collection as net/mrouted.

   MBONE tools are available in their own ports category, mbone. If
   you are looking for the conference tools vic and vat, look there!

   12.15. Which network cards are based on the DEC PCI chipset?

   Here is a list compiled by Glen Foster <gfoster@driver.nsta.org>,
   with some more modern additions:

   Table 12-1. Network Cards Based on the DEC PCI Chipset

   +----------------------------------------------------------------+
   |    Vendor    |                      Model                      |
   |--------------+-------------------------------------------------|
   | ASUS         | PCI-L101-TB                                     |
   |--------------+-------------------------------------------------|
   | Accton       | ENI1203                                         |
   |--------------+-------------------------------------------------|
   | Cogent       | EM960PCI                                        |
   |--------------+-------------------------------------------------|
   | Compex       | ENET32-PCI                                      |
   |--------------+-------------------------------------------------|
   | D-Link       | DE-530                                          |
   |--------------+-------------------------------------------------|
   | Dayna        | DP1203, DP2100                                  |
   |--------------+-------------------------------------------------|
   | DEC          | DE435, DE450                                    |
   |--------------+-------------------------------------------------|
   | Danpex       | EN-9400P3                                       |
   |--------------+-------------------------------------------------|
   | JCIS         | Condor JC1260                                   |
   |--------------+-------------------------------------------------|
   | Linksys      | EtherPCI                                        |
   |--------------+-------------------------------------------------|
   | Mylex        | LNP101                                          |
   |--------------+-------------------------------------------------|
   | SMC          | EtherPower 10/100 (Model 9332)                  |
   |--------------+-------------------------------------------------|
   | SMC          | EtherPower (Model 8432)                         |
   |--------------+-------------------------------------------------|
   | TopWare      | TE-3500P                                        |
   |--------------+-------------------------------------------------|
   | Znyx (2.2.x) | ZX312, ZX314, ZX342, ZX345, ZX346, ZX348        |
   |--------------+-------------------------------------------------|
   | Znyx (3.x)   | ZX345Q, ZX346Q, ZX348Q, ZX412Q, ZX414, ZX442,   |
   |              | ZX444, ZX474, ZX478, ZX212, ZX214 (10mbps/hd)   |
   +----------------------------------------------------------------+

   12.16. Why do I have to use the FQDN for hosts on my site?

   See the answer in the FreeBSD Handbook.

   12.17. Why do I get an error, "Permission denied", for all
   networking operations?

   If you have compiled your kernel with the IPFIREWALL option, you
   need to be aware that the default policy is to deny all packets
   that are not explicitly allowed.

   If you had unintentionally misconfigured your system for
   firewalling, you can restore network operability by typing the
   following while logged in as root:

 # ipfw add 65534 allow all from any to any

   You can also set firewall_type="open" in /etc/rc.conf.

   For further information on configuring a FreeBSD firewall, see the
   Handbook chapter.

   12.18. Why is my ipfw "fwd" rule to redirect a service to another
   machine not working?

   Possibly because you want to do network address translation (NAT)
   and not just forward packets. A "fwd" rule does exactly what it
   says; it forwards packets. It does not actually change the data
   inside the packet. Say we have a rule like:

 01000 fwd 10.0.0.1 from any to foo 21

   When a packet with a destination address of foo arrives at the
   machine with this rule, the packet is forwarded to 10.0.0.1, but
   it still has the destination address of foo! The destination
   address of the packet is not changed to 10.0.0.1. Most machines
   would probably drop a packet that they receive with a destination
   address that is not their own. Therefore, using a "fwd" rule does
   not often work the way the user expects. This behavior is a
   feature and not a bug.

   See the FAQ about redirecting services, the natd(8) manual, or one
   of the several port redirecting utilities in the Ports Collection
   for a correct way to do this.

   12.19. How can I redirect service requests from one machine to
   another?

   You can redirect FTP (and other service) request with the
   sysutils/socket port. Simply replace the service's command line to
   call socket instead, like so:

 ftp stream tcp nowait nobody /usr/local/bin/socket socket ftp.example.com ftp

   where ftp.example.com and ftp are the host and port to redirect
   to, respectively.

   12.20. Where can I get a bandwidth management tool?

   There are three bandwidth management tools available for FreeBSD.
   dummynet(4) is integrated into FreeBSD as part of ipfw(4). ALTQ
   has been integrated into FreeBSD as part of pf(4). Bandwidth
   Manager from Emerging Technologies is a commercial product.

   12.21. Why do I get "/dev/bpf0: device not configured"?

   You are running a program that requires the Berkeley Packet Filter
   (bpf(4)), but it is not in your kernel. Add this to your kernel
   config file and build a new kernel:

 device bpf        # Berkeley Packet Filter

   12.22. How do I mount a disk from a Windows machine that is on my
   network, like smbmount in Linux?

   Use the SMBFS toolset. It includes a set of kernel modifications
   and a set of userland programs. The programs and information are
   available as mount_smbfs(8) in the base system.

   12.23. What are these messages about: "Limiting icmp/open
   port/closed port response" in my log files?

   This is the kernel telling you that some activity is provoking it
   to send more ICMP or TCP reset (RST) responses than it thinks it
   should. ICMP responses are often generated as a result of
   attempted connections to unused UDP ports. TCP resets are
   generated as a result of attempted connections to unopened TCP
   ports. Among others, these are the kinds of activities which may
   cause these messages:

     * Brute-force denial of service (DoS) attacks (as opposed to
       single-packet attacks which exploit a specific vulnerability).

     * Port scans which attempt to connect to a large number of ports
       (as opposed to only trying a few well-known ports).

   The first number in the message tells you how many packets the
   kernel would have sent if the limit was not in place, and the
   second number tells you the limit. You can control the limit using
   the net.inet.icmp.icmplim sysctl variable like this, where 300 is
   the limit in packets per second:

 # sysctl -w net.inet.icmp.icmplim=300

   If you do not want to see messages about this in your log files,
   but you still want the kernel to do response limiting, you can use
   the net.inet.icmp.icmplim_output sysctl variable to disable the
   output like this:

 # sysctl -w net.inet.icmp.icmplim_output=0

   Finally, if you want to disable response limiting, you can set the
   net.inet.icmp.icmplim sysctl variable (see above for an example)
   to 0. Disabling response limiting is discouraged for the reasons
   listed above.

   12.24. What are these "arp: unknown hardware address format" error
   messages?

   This means that some device on your local Ethernet is using a MAC
   address in a format that FreeBSD does not recognize. This is
   probably caused by someone experimenting with an Ethernet card
   somewhere else on the network. You will see this most commonly on
   cable modem networks. It is harmless, and should not affect the
   performance of your FreeBSD machine.

   12.25. Why do I keep seeing messages like: "192.168.0.10 is on
   fxp1 but got reply from 00:15:17:67:cf:82 on rl0", and how do I
   disable it?

   Because a packet is coming from outside the network unexpectedly.
   To disable them, set net.link.ether.inet.log_arp_wrong_iface to 0.

   12.26. I have just installed CVSup but trying to execute it
   produces errors. What is wrong?

   First, see if the error message you are receiving is like the one
   shown below.

 /usr/libexec/ld-elf.so.1: Shared object "libXaw.so.6" not found

   Errors like these are caused by installing the net/cvsup port on a
   machine which does not have the Xorg suite. If you want to use the
   GUI included with CVSup you will need to install Xorg now.
   Alternatively if you just wish to use CVSup from a command line
   you should delete the package previously installed. Then install
   the net/cvsup-without-gui or the net/csup port. If you have a
   recent FreeBSD release you may use csup(1). This is covered in
   more detail in the CVSup section of the Handbook.

     --------------------------------------------------------------

                          Chapter 13 Security

   13.1. What is a sandbox?

   13.2. What is securelevel?

   13.3. BIND (named) is listening on some high-numbered ports. What
   is going on?

   13.4. The sendmail daemon is listening on port 587 as well as the
   standard port 25! What is going on?

   13.5. What is this UID 0 toor account? Have I been compromised?

   13.6. Why is suidperl not working properly?

   13.1. What is a sandbox?

   "Sandbox" is a security term. It can mean two things:

     * A process which is placed inside a set of virtual walls that
       are designed to prevent someone who breaks into the process
       from being able to break into the wider system.

       The process is said to be able to "play" inside the walls.
       That is, nothing the process does in regards to executing code
       is supposed to be able to breech the walls so you do not have
       to do a detailed audit of its code to be able to say certain
       things about its security.

       The walls might be a user ID, for example. This is the
       definition used in the security(7) and named(8) man pages.

       Take the ntalk service, for example (see inetd(8)). This
       service used to run as user ID root. Now it runs as user ID
       tty. The tty user is a sandbox designed to make it more
       difficult for someone who has successfully hacked into the
       system via ntalk from being able to hack beyond that user ID.

     * A process which is placed inside a simulation of the machine.
       This is more hard-core. Basically it means that someone who is
       able to break into the process may believe that he can break
       into the wider machine but is, in fact, only breaking into a
       simulation of that machine and not modifying any real data.

       The most common way to accomplish this is to build a simulated
       environment in a subdirectory and then run the processes in
       that directory chroot'd (i.e. / for that process is this
       directory, not the real / of the system).

       Another common use is to mount an underlying file system
       read-only and then create a file system layer on top of it
       that gives a process a seemingly writeable view into that file
       system. The process may believe it is able to write to those
       files, but only the process sees the effects -- other
       processes in the system do not, necessarily.

       An attempt is made to make this sort of sandbox so transparent
       that the user (or hacker) does not realize that he is sitting
       in it.

   UNIX implements two core sandboxes. One is at the process level,
   and one is at the userid level.

   Every UNIX process is completely firewalled off from every other
   UNIX process. One process cannot modify the address space of
   another. This is unlike Windows where a process can easily
   overwrite the address space of any other, leading to a crash.

   A UNIX process is owned by a particular userid. If the user ID is
   not the root user, it serves to firewall the process off from
   processes owned by other users. The user ID is also used to
   firewall off on-disk data.

   13.2. What is securelevel?

   The securelevel is a security mechanism implemented in the kernel.
   Basically, when the securelevel is positive, the kernel restricts
   certain tasks; not even the superuser (i.e., root) is allowed to
   do them. At the time of this writing, the securelevel mechanism is
   capable of, among other things, limiting the ability to:

     * Unset certain file flags, such as schg (the system immutable
       flag).

     * Write to kernel memory via /dev/mem and /dev/kmem.

     * Load kernel modules.

     * Alter firewall rules.

   To check the status of the securelevel on a running system, simply
   execute the following command:

 # sysctl kern.securelevel

   The output will contain the name of the sysctl(8) variable (in
   this case, kern.securelevel) and a number. The latter is the
   current value of the securelevel. If it is positive (i.e., greater
   than 0), at least some of the securelevel's protections are
   enabled.

   You cannot lower the securelevel of a running system; being able
   to do that would defeat its purpose. If you need to do a task that
   requires that the securelevel be non-positive (e.g., an
   installworld or changing the date), you will have to change the
   securelevel setting in /etc/rc.conf (you want to look for the
   kern_securelevel and kern_securelevel_enable variables) and
   reboot.

   For more information on securelevel and the specific things all
   the levels do, please consult the init(8) manual page.

     Warning: Securelevel is not a silver bullet; it has many known
     deficiencies. More often than not, it provides a false sense of
     security.

     One of its biggest problems is that in order for it to be at all
     effective, all files used in the boot process up until the
     securelevel is set must be protected. If an attacker can get the
     system to execute their code prior to the securelevel being set
     (which happens quite late in the boot process since some things
     the system must do at start-up cannot be done at an elevated
     securelevel), its protections are invalidated. While this task
     of protecting all files used in the boot process is not
     technically impossible, if it is achieved, system maintenance
     will become a nightmare since one would have to take the system
     down, at least to single-user mode, to modify a configuration
     file.

     This point and others are often discussed on the mailing lists,
     particularly the FreeBSD security mailing list. Please search
     the archives here for an extensive discussion. Some people are
     hopeful that securelevel will soon go away in favor of a more
     fine-grained mechanism, but things are still hazy in this
     respect.

     Consider yourself warned.

   13.3. BIND (named) is listening on some high-numbered ports. What
   is going on?

   BIND uses a random high-numbered port for outgoing queries. Recent
   versions of it choose a new, random UDP port for each query. This
   may cause problems for some network configurations, especially if
   a firewall blocks incoming UDP packets on particular ports. If you
   want to get past that firewall, you can try the avoid-v4-udp-ports
   and avoid-v6-udp-ports options to avoid selecting random port
   numbers within a blocked range.

     Warning: If a port number (like 53) is specified via the
     query-source or query-source-v6 options in
     /etc/namedb/named.conf, randomized port selection will not be
     used. It is strongly recommended that these options not be used
     to specify fixed port numbers.

   Congratulations, by the way. It is good practice to read your
   sockstat(1) output and notice odd things!

   13.4. The sendmail daemon is listening on port 587 as well as the
   standard port 25! What is going on?

   Recent versions of sendmail support a mail submission feature that
   runs over port 587. This is not yet widely supported, but is
   growing in popularity.

   13.5. What is this UID 0 toor account? Have I been compromised?

   Do not worry. toor is an "alternative" superuser account (toor is
   root spelt backwards). Previously it was created when the bash(1)
   shell was installed but now it is created by default. It is
   intended to be used with a non-standard shell so you do not have
   to change root's default shell. This is important as shells which
   are not part of the base distribution (for example a shell
   installed from ports or packages) are likely to be installed in
   /usr/local/bin which, by default, resides on a different file
   system. If root's shell is located in /usr/local/bin and /usr (or
   whatever file system contains /usr/local/bin) is not mounted for
   some reason, root will not be able to log in to fix a problem
   (although if you reboot into single user mode you will be prompted
   for the path to a shell).

   Some people use toor for day-to-day root tasks with a non-standard
   shell, leaving root, with a standard shell, for single user mode
   or emergencies. By default you cannot log in using toor as it does
   not have a password, so log in as root and set a password for toor
   if you want to use it.

   13.6. Why is suidperl not working properly?

   For security reasons, suidperl is not installed by default. If you
   want suidperl to be built during upgrades from source, edit
   /etc/make.conf and add ENABLE_SUIDPERL=true before you build perl.

     --------------------------------------------------------------

                             Chapter 14 PPP

   14.1. I cannot make ppp(8) work. What am I doing wrong?

   14.2. Why does ppp(8) hang when I run it?

   14.3. Why will ppp(8) not dial in -auto mode?

   14.4. What does "No route to host" mean?

   14.5. Why does my connection drop after about 3 minutes?

   14.6. Why does my connection drop under heavy load?

   14.7. Why does my connection drop after a random amount of time?

   14.8. Why does my connection hang after a random amount of time?

   14.9. The remote end is not responding. What can I do?

   14.10. ppp(8) has hung. What can I do?

   14.11. Why does nothing happen after the "Login OK!" message?

   14.12. I keep seeing errors about magic being the same. What does
   it mean?

   14.13. LCP negotiations continue until the connection is closed.
   What is wrong?

   14.14. Why does ppp(8) lock up when I shell out to test it?

   14.15. Why does ppp(8) over a null-modem cable never exit?

   14.16. Why does ppp(8) dial for no reason in -auto mode?

   14.17. What do these CCP errors mean?

   14.18. Why does ppp(8) not log my connection speed?

   14.19. Why does ppp(8) ignore the \ character in my chat script?

   14.20. Why does ppp(8) get a "Segmentation fault", but I see no
   ppp.core file?

   14.21. Why does the process that forces a dial in -auto mode never
   connect?

   14.22. Why do most games not work with the -nat switch?

   14.23. Has anybody made a list of useful port numbers?

   14.24. What are FCS errors?

   14.25. Why do Mac OS and Windows 98 connections freeze when
   running PPPoE on the gateway?

   14.26. None of this helps -- I am desperate! What can I do?

   14.1. I cannot make ppp(8) work. What am I doing wrong?

   You should first read the ppp(8) manual page and the PPP section
   of the handbook. Enable logging with the following command:

 set log Phase Chat Connect Carrier lcp ipcp ccp command

   This command may be typed at the ppp(8) command prompt or it may
   be entered in the /etc/ppp/ppp.conf configuration file (the start
   of the default section is the best place to put it). Make sure
   that /etc/syslog.conf (see syslog.conf(5)) contains the lines
   below and the file /var/log/ppp.log exists:

 !ppp
 *.*        /var/log/ppp.log

   You can now find out a lot about what is going on from the log
   file. Do not worry if it does not all make sense. If you need to
   get help from someone, it may make sense to them.

   14.2. Why does ppp(8) hang when I run it?

   This is usually because your hostname will not resolve. The best
   way to fix this is to make sure that /etc/hosts is consulted by
   your resolver first by editing /etc/host.conf and putting the
   hosts line first. Then, simply put an entry in /etc/hosts for your
   local machine. If you have no local network, change your localhost
   line:

 127.0.0.1        foo.example.com foo localhost

   Otherwise, simply add another entry for your host. Consult the
   relevant manual pages for more details.

   You should be able to successfully ping -c1 `hostname` when you
   are done.

   14.3. Why will ppp(8) not dial in -auto mode?

   First, check that you have got a default route. By running netstat
   -rn (see netstat(1)), you should see two entries like this:

 Destination        Gateway            Flags     Refs     Use     Netif Expire
 default            10.0.0.2           UGSc        0        0      tun0
 10.0.0.2           10.0.0.1           UH          0        0      tun0

   This is assuming that you have used the addresses from the
   handbook, the manual page, or from the ppp.conf.sample file. If
   you do not have a default route, it may be because you forgot to
   add the HISADDR line to the ppp.conf file.

   Another reason for the default route line being missing is that
   you have mistakenly set up a default router in your /etc/rc.conf
   (see rc.conf(5)) file and you have omitted the line below from
   ppp.conf:

 delete ALL

   If this is the case, go back to the Final System Configuration
   section of the handbook.

   14.4. What does "No route to host" mean?

   This error is usually due that the following section is missing in
   your /etc/ppp/ppp.linkup file:

 MYADDR:
   delete ALL
   add 0 0 HISADDR

   This is only necessary if you have a dynamic IP address or do not
   know the address of your gateway. If you are using interactive
   mode, you can type the following after entering packet mode
   (packet mode is indicated by the capitalized PPP in the prompt):

 delete ALL
 add 0 0 HISADDR

   Refer to the PPP and Dynamic IP addresses section of the handbook
   for further details.

   14.5. Why does my connection drop after about 3 minutes?

   The default PPP timeout is 3 minutes. This can be adjusted with
   the following line:

 set timeout NNN

   where NNN is the number of seconds of inactivity before the
   connection is closed. If NNN is zero, the connection is never
   closed due to a timeout. It is possible to put this command in the
   ppp.conf file, or to type it at the prompt in interactive mode. It
   is also possible to adjust it on the fly while the line is active
   by connecting to ppp's server socket using telnet(1) or pppctl(8).
   Refer to the ppp(8) man page for further details.

   14.6. Why does my connection drop under heavy load?

   If you have Link Quality Reporting (LQR) configured, it is
   possible that too many LQR packets are lost between your machine
   and the peer. The ppp(8) program deduces that the line must
   therefore be bad, and disconnects. Prior to FreeBSD version 2.2.5,
   LQR was enabled by default. It is now disabled by default. LQR can
   be disabled with the following line:

 disable lqr

   14.7. Why does my connection drop after a random amount of time?

   Sometimes, on a noisy phone line or even on a line with call
   waiting enabled, your modem may hang up because it thinks
   (incorrectly) that it lost carrier.

   There is a setting on most modems for determining how tolerant it
   should be to temporary losses of carrier. On a U.S.
   Robotics(R) Sportster(R) for example, this is measured by the S10
   register in tenths of a second. To make your modem more forgiving,
   you could add the following send-expect sequence to your dial
   string:

 set dial "...... ATS10=10 OK ......"

   Refer to your modem manual for details.

   14.8. Why does my connection hang after a random amount of time?

   Many people experience hung connections with no apparent
   explanation. The first thing to establish is which side of the
   link is hung.

   If you are using an external modem, you can simply try using
   ping(8) to see if the TD light is flashing when you transmit data.
   If it flashes (and the RD light does not), the problem is with the
   remote end. If TD does not flash, the problem is local. With an
   internal modem, you will need to use the set server command in
   your ppp.conf file. When the hang occurs, connect to ppp(8) using
   pppctl(8). If your network connection suddenly revives (PPP was
   revived due to the activity on the diagnostic socket) or if you
   cannot connect (assuming the set socket command succeeded at
   startup time), the problem is local. If you can connect and things
   are still hung, enable local async logging with set log local
   async and use ping(8) from another window or terminal to make use
   of the link. The async logging will show you the data being
   transmitted and received on the link. If data is going out and not
   coming back, the problem is remote.

   Having established whether the problem is local or remote, you now
   have two possibilities:

     * If the problem is remote, read on entry Q: 14.9..

     * If the problem is local, read on entry Q: 14.10..

   14.9. The remote end is not responding. What can I do?

   There is very little you can do about this. Most ISPs will refuse
   to help if you are not running a Microsoft OS. You can enable lqr
   in your ppp.conf file, allowing ppp(8) to detect the remote
   failure and hang up, but this detection is relatively slow and
   therefore not that useful. You may want to avoid telling your ISP
   that you are running user-PPP.

   First, try disabling all local compression by adding the following
   to your configuration:

 disable pred1 deflate deflate24 protocomp acfcomp shortseq vj
 deny pred1 deflate deflate24 protocomp acfcomp shortseq vj

   Then reconnect to ensure that this makes no difference. If things
   improve or if the problem is solved completely, determine which
   setting makes the difference through trial and error. This will
   provide good ammunition when you contact your ISP (although it may
   make it apparent that you are not running a Microsoft product).

   Before contacting your ISP, enable async logging locally and wait
   until the connection hangs again. This may use up quite a bit of
   disk space. The last data read from the port may be of interest.
   It is usually ASCII data, and may even describe the problem
   ("Memory fault", "Core dumped").

   If your ISP is helpful, they should be able to enable logging on
   their end, then when the next link drop occurs, they may be able
   to tell you why their side is having a problem. Feel free to send
   the details to Brian Somers <brian@FreeBSD.org>, or even to ask
   your ISP to contact him directly.

   14.10. ppp(8) has hung. What can I do?

   Your best bet here is to rebuild ppp(8) with debugging
   information, and then use gdb(1) to grab a stack trace from the
   ppp process that is stuck. To rebuild the ppp utility with
   debugging information, you can type:

 # cd /usr/src/usr.sbin/ppp
 # env DEBUG_FLAGS='-g' make clean
 # env DEBUG_FLAGS='-g' make install

   Then you should restart ppp and wait until it hangs again. When
   the debug build of ppp hangs, start gdb on the stuck process by
   typing:

 # gdb ppp `pgrep ppp`

   At the gdb prompt, you can use the bt or where commands to get a
   stack trace. Save the output of your gdb session, and "detach"
   from the running process by the quit command of gdb.

   Finally, send the log of your gdb session to Brian Somers
   <brian@FreeBSD.org>.

   14.11. Why does nothing happen after the "Login OK!" message?

   Prior to FreeBSD version 2.2.5, once the link was established,
   ppp(8) would wait for the peer to initiate the Line Control
   Protocol (LCP). Many ISPs will not initiate negotiations and
   expect the client to do so. To force ppp(8) to initiate the LCP,
   use the following line:

 set openmode active

     Note: It usually does no harm if both sides initiate
     negotiation, so openmode is now active by default. However, the
     next section explains when it does do some harm.

   14.12. I keep seeing errors about magic being the same. What does
   it mean?

   Occasionally, just after connecting, you may see messages in the
   log that say "Magic is same". Sometimes, these messages are
   harmless, and sometimes one side or the other exits. Most PPP
   implementations cannot survive this problem, and even if the link
   seems to come up, you will see repeated configure requests and
   configure acknowledgments in the log file until ppp(8) eventually
   gives up and closes the connection.

   This normally happens on server machines with slow disks that are
   spawning a getty(8) on the port, and executing ppp(8) from a login
   script or program after login. There were reports of it happening
   consistently when using slirp. The reason is that in the time
   taken between getty(8) exiting and ppp(8) starting, the
   client-side ppp(8) starts sending Line Control Protocol (LCP)
   packets. Because ECHO is still switched on for the port on the
   server, the client ppp(8) sees these packets "reflect" back.

   One part of the LCP negotiation is to establish a magic number for
   each side of the link so that "reflections" can be detected. The
   protocol says that when the peer tries to negotiate the same magic
   number, a NAK should be sent and a new magic number should be
   chosen. During the period that the server port has ECHO turned on,
   the client ppp(8) sends LCP packets, sees the same magic in the
   reflected packet and NAKs it. It also sees the NAK reflect (which
   also means ppp(8) must change its magic). This produces a
   potentially enormous number of magic number changes, all of which
   are happily piling into the server's tty buffer. As soon as ppp(8)
   starts on the server, it is flooded with magic number changes and
   almost immediately decides it has tried enough to negotiate LCP
   and gives up. Meanwhile, the client, who no longer sees the
   reflections, becomes happy just in time to see a hangup from the
   server.

   This can be avoided by allowing the peer to start negotiating with
   the following line in your ppp.conf file:

 set openmode passive

   This tells ppp(8) to wait for the server to initiate LCP
   negotiations. Some servers however may never initiate
   negotiations. If this is the case, you can do something like:

 set openmode active 3

   This tells ppp(8) to be passive for 3 seconds, and then to start
   sending LCP requests. If the peer starts sending requests during
   this period, ppp(8) will immediately respond rather than waiting
   for the full 3 second period.

   14.13. LCP negotiations continue until the connection is closed.
   What is wrong?

   There is currently an implementation mis-feature in ppp(8) where
   it does not associate LCP, CCP & IPCP responses with their
   original requests. As a result, if one PPP implementation is more
   than 6 seconds slower than the other side, the other side will
   send two additional LCP configuration requests. This is fatal.

   Consider two implementations, A and B. A starts sending LCP
   requests immediately after connecting and B takes 7 seconds to
   start. When B starts, A has sent 3 LCP REQs. We are assuming the
   line has ECHO switched off, otherwise we would see magic number
   problems as described in the previous section. B sends a REQ, then
   an ACK to the first of A's REQs. This results in A entering the
   OPENED state and sending and ACK (the first) back to B. In the
   meantime, B sends back two more ACKs in response to the two
   additional REQs sent by A before B started up. B then receives the
   first ACK from A and enters the OPENED state. A receives the
   second ACK from B and goes back to the REQ-SENT state, sending
   another (forth) REQ as per the RFC. It then receives the third ACK
   and enters the OPENED state. In the meantime, B receives the forth
   REQ from A, resulting in it reverting to the ACK-SENT state and
   sending another (second) REQ and (forth) ACK as per the RFC. A
   gets the REQ, goes into REQ-SENT and sends another REQ. It
   immediately receives the following ACK and enters OPENED.

   This goes on until one side figures out that they are getting
   nowhere and gives up.

   The best way to avoid this is to configure one side to be passive
   -- that is, make one side wait for the other to start negotiating.
   This can be done with the following command:

 set openmode passive

   Care should be taken with this option. You should also use this
   command to limit the amount of time that ppp(8) waits for the peer
   to begin negotations:

 set stopped N

   Alternatively, the following command (where N is the number of
   seconds to wait before starting negotiations) can be used:

 set openmode active N

   Check the manual page for details.

   14.14. Why does ppp(8) lock up when I shell out to test it?

   When you execute the shell or ! command, ppp(8) executes a shell
   (or if you have passed any arguments, ppp(8) will execute those
   arguments). The ppp program will wait for the command to complete
   before continuing. If you attempt to use the PPP link while
   running the command, the link will appear to have frozen. This is
   because ppp(8) is waiting for the command to complete.

   If you wish to execute commands like this, use the !bg command
   instead. This will execute the given command in the background,
   and ppp(8) can continue to service the link.

   14.15. Why does ppp(8) over a null-modem cable never exit?

   There is no way for ppp(8) to automatically determine that a
   direct connection has been dropped. This is due to the lines that
   are used in a null-modem serial cable. When using this sort of
   connection, LQR should always be enabled with the following line:

 enable lqr

   LQR is accepted by default if negotiated by the peer.

   14.16. Why does ppp(8) dial for no reason in -auto mode?

   If ppp(8) is dialing unexpectedly, you must determine the cause,
   and set up Dial filters (dfilters) to prevent such dialing.

   To determine the cause, use the following line:

 set log +tcp/ip

   This will log all traffic through the connection. The next time
   the line comes up unexpectedly, you will see the reason logged
   with a convenient timestamp next to it.

   You can now disable dialing under these circumstances. Usually,
   this sort of problem arises due to DNS lookups. To prevent DNS
   lookups from establishing a connection (this will not prevent
   ppp(8) from passing the packets through an established
   connection), use the following:

 set dfilter 1 deny udp src eq 53
 set dfilter 2 deny udp dst eq 53
 set dfilter 3 permit 0/0 0/0

   This is not always suitable, as it will effectively break your
   demand-dial capabilities -- most programs will need a DNS lookup
   before doing any other network related things.

   In the DNS case, you should try to determine what is actually
   trying to resolve a host name. A lot of the time, sendmail(8) is
   the culprit. You should make sure that you tell sendmail not to do
   any DNS lookups in its configuration file. See the section on
   using email with a dialup connection in the FreeBSD Handbook for
   details on how to create your own configuration file and what
   should go into it. You may also want to add the following line to
   your .mc file:

 define(`confDELIVERY_MODE', `d')dnl

   This will make sendmail queue everything until the queue is run
   (usually, sendmail is invoked with -bd -q30m, telling it to run
   the queue every 30 minutes) or until a sendmail -q is done
   (perhaps from your ppp.linkup file).

   14.17. What do these CCP errors mean?

   I keep seeing the following errors in my log file:

 CCP: CcpSendConfigReq
 CCP: Received Terminate Ack (1) state = Req-Sent (6)

   This is because ppp(8) is trying to negotiate Predictor1
   compression, and the peer does not want to negotiate any
   compression at all. The messages are harmless, but if you wish to
   remove them, you can disable Predictor1 compression locally too:

 disable pred1

   14.18. Why does ppp(8) not log my connection speed?

   In order to log all lines of your modem "conversation", you must
   enable the following:

 set log +connect

   This will make ppp(8) log everything up until the last requested
   "expect" string.

   If you wish to see your connect speed and are using PAP or CHAP
   (and therefore do not have anything to "chat" after the CONNECT in
   the dial script -- no set login script), you must make sure that
   you instruct ppp(8) to "expect" the whole CONNECT line, something
   like this:

 set dial "ABORT BUSY ABORT NO\\sCARRIER TIMEOUT 4 \
   \"\" ATZ OK-ATZ-OK ATDT\\T TIMEOUT 60 CONNECT \\c \\n"

   Here, we get our CONNECT, send nothing, then expect a line-feed,
   forcing ppp(8) to read the whole CONNECT response.

   14.19. Why does ppp(8) ignore the \ character in my chat script?

   The ppp utility parses each line in your config files so that it
   can interpret strings such as set phone "123 456 789" correctly
   and realize that the number is actually only one argument. In
   order to specify a " character, you must escape it using a
   backslash (\).

   When the chat interpreter parses each argument, it re-interprets
   the argument in order to find any special escape sequences such as
   \P or \T (see the manual page). As a result of this
   double-parsing, you must remember to use the correct number of
   escapes.

   If you wish to actually send a \ character to (say) your modem,
   you would need something like:

 set dial "\"\" ATZ OK-ATZ-OK AT\\\\X OK"

   It will result in the following sequence:

 ATZ
 OK
 AT\X
 OK

   Or:

 set phone 1234567
 set dial "\"\" ATZ OK ATDT\\T"

   It will result in the following sequence:

 ATZ
 OK
 ATDT1234567

   14.20. Why does ppp(8) get a "Segmentation fault", but I see no
   ppp.core file?

   The ppp utility (or any other program for that matter) should
   never dump core. Because ppp(8) runs with an effective user ID of
   0, the operating system will not write core image of ppp(8) to
   disk before terminating it. If, however ppp(8) is actually
   terminating due to a segmentation violation or some other signal
   that normally causes core to be dumped, and you are sure you are
   using the latest version (see the start of this section), then you
   should install the system sources and do the following:

 #  cd /usr/src/usr.sbin/ppp
 # echo STRIP= >> /etc/make.conf
 # echo CFLAGS+=-g >> /etc/make.conf
 # make install clean

   You will now have a debuggable version of ppp(8) installed. You
   will have to be root to run ppp(8) as all of its privileges have
   been revoked. When you start ppp(8), take a careful note of what
   your current directory was at the time.

   Now, if and when ppp(8) receives the segmentation violation, it
   will dump a core file called ppp.core. You should then do the
   following:

 % su
 # gdb /usr/sbin/ppp ppp.core
 (gdb) bt
 .....
 (gdb) f 0
 ....
 (gdb) i args
 ....
 (gdb) l
 .....

   All of this information should be given alongside your question,
   making it possible to diagnose the problem.

   If you are familiar with gdb(1), you may wish to find out some
   other bits and pieces such as what actually caused the dump or the
   addresses and values of the relevant variables.

   14.21. Why does the process that forces a dial in -auto mode never
   connect?

   This was a known problem with ppp(8) set up to negotiate a dynamic
   local IP number with the peer in -auto mode. It has been fixed a
   long time ago -- search the manual page for iface.

   The problem was that when that initial program calls connect(2),
   the IP number of the tun(4) interface is assigned to the socket
   endpoint. The kernel creates the first outgoing packet and writes
   it to the tun(4) device. ppp(8) then reads the packet and
   establishes a connection. If, as a result of ppp(8)'s dynamic IP
   assignment, the interface address is changed, the original socket
   endpoint will be invalid. Any subsequent packets sent to the peer
   will usually be dropped. Even if they are not, any responses will
   not route back to the originating machine as the IP number is no
   longer owned by that machine.

   There are several theoretical ways to approach this problem. It
   would be nicest if the peer would re-assign the same IP number if
   possible. The current version of ppp(8) does this, but most other
   implementations do not.

   The easiest method from our side would be to never change the
   tun(4) interface IP number, but instead to change all outgoing
   packets so that the source IP number is changed from the interface
   IP to the negotiated IP on the fly. This is essentially what the
   iface-alias option in the latest version of ppp(8) is doing (with
   the help of libalias(3) and ppp(8)'s -nat switch) -- it is
   maintaining all previous interface addresses and NATing them to
   the last negotiated address.

   Another alternative (and probably the most reliable) would be to
   implement a system call that changes all bound sockets from one IP
   to another. ppp(8) would use this call to modify the sockets of
   all existing programs when a new IP number is negotiated. The same
   system call could be used by DHCP clients when they are forced to
   call the bind() function for their sockets.

   Yet another possibility is to allow an interface to be brought up
   without an IP number. Outgoing packets would be given an IP number
   of 255.255.255.255 up until the first SIOCAIFADDR ioctl(2) is
   done. This would result in fully binding the socket. It would be
   up to ppp(8) to change the source IP number, but only if it is set
   to 255.255.255.255, and only the IP number and IP checksum would
   need to change. This, however is a bit of a hack as the kernel
   would be sending bad packets to an improperly configured
   interface, on the assumption that some other mechanism is capable
   of fixing things retrospectively.

   14.22. Why do most games not work with the -nat switch?

   The reason games and the like do not work when libalias(3) is in
   use is that the machine on the outside will try to open a
   connection or send (unsolicited) UDP packets to the machine on the
   inside. The NAT software does not know that it should send these
   packets to the interior machine.

   To make things work, make sure that the only thing running is the
   software that you are having problems with, then either run
   tcpdump(1) on the tun(4) interface of the gateway or enable ppp(8)
   TCP/IP logging (set log +tcp/ip) on the gateway.

   When you start the offending software, you should see packets
   passing through the gateway machine. When something comes back
   from the outside, it will be dropped (that is the problem). Note
   the port number of these packets then shut down the offending
   software. Do this a few times to see if the port numbers are
   consistent. If they are, then the following line in the relevant
   section of /etc/ppp/ppp.conf will make the software functional:

 nat port proto internalmachine:port port

   where proto is either tcp or udp, internalmachine is the machine
   that you want the packets to be sent to and port is the
   destination port number of the packets.

   You will not be able to use the software on other machines without
   changing the above command, and running the software on two
   internal machines at the same time is out of the question -- after
   all, the outside world is seeing your entire internal network as
   being just a single machine.

   If the port numbers are not consistent, there are three more
   options:

    1. Submit support in libalias(3). Examples of "special cases" can
       be found in /usr/src/sys/netinet/libalias/alias_*.c
       (alias_ftp.c is a good prototype). This usually involves
       reading certain recognised outgoing packets, identifying the
       instruction that tells the outside machine to initiate a
       connection back to the internal machine on a specific (random)
       port and setting up a "route" in the alias table so that the
       subsequent packets know where to go.

       This is the most difficult solution, but it is the best and
       will make the software work with multiple machines.

    2. Use a proxy. The application may support socks5 for example,
       or (as in the cvsup case) may have a "passive" option that
       avoids ever requesting that the peer open connections back to
       the local machine.

    3. Redirect everything to the internal machine using nat addr.
       This is the sledge-hammer approach.

   14.23. Has anybody made a list of useful port numbers?

   Not yet, but this is intended to grow into such a list (if any
   interest is shown). In each example, internal should be replaced
   with the IP number of the machine playing the game.

     * Asheron's Call

       nat port udp internal :65000 65000

       Manually change the port number within the game to 65000. If
       you have got a number of machines that you wish to play on
       assign a unique port number for each (i.e. 65001, 65002, etc)
       and add a nat port line for each one.

     * Half Life

       nat port udp internal:27005 27015

     * PCAnywhere 8.0

       nat port udp internal:5632 5632

       nat port tcp internal:5631 5631

     * Quake

       nat port udp internal:6112 6112

     * Quake 2

       nat port udp internal:27901 27910

       nat port udp internal:60021 60021

       nat port udp internal:60040 60040

     * Red Alert

       nat port udp internal:8675 8675

       nat port udp internal:5009 5009

   14.24. What are FCS errors?

   FCS stands for Frame Check Sequence. Each PPP packet has a
   checksum attached to ensure that the data being received is the
   data being sent. If the FCS of an incoming packet is incorrect,
   the packet is dropped and the HDLC FCS count is increased. The
   HDLC error values can be displayed using the show hdlc command.

   If your link is bad (or if your serial driver is dropping
   packets), you will see the occasional FCS error. This is not
   usually worth worrying about although it does slow down the
   compression protocols substantially. If you have an external
   modem, make sure your cable is properly shielded from interference
   -- this may eradicate the problem.

   If your link freezes as soon as you have connected and you see a
   large number of FCS errors, this may be because your link is not
   8-bit clean. Make sure your modem is not using software flow
   control (XON/XOFF). If your datalink must use software flow
   control, use the command set accmap 0x000a0000 to tell ppp(8) to
   escape the ^Q and ^S characters.

   Another reason for seeing too many FCS errors may be that the
   remote end has stopped talking PPP. You may want to enable async
   logging at this point to determine if the incoming data is
   actually a login or shell prompt. If you have a shell prompt at
   the remote end, it is possible to terminate ppp(8) without
   dropping the line by using the close lcp command (a following term
   command) will reconnect you to the shell on the remote machine.

   If nothing in your log file indicates why the link might have been
   terminated, you should ask the remote administrator (your ISP?)
   why the session was terminated.

   14.25. Why do Mac OS and Windows 98 connections freeze when
   running PPPoE on the gateway?

   Thanks to Michael Wozniak <mwozniak@netcom.ca> for figuring this
   out and Dan Flemming <danflemming@mac.com> for the Mac solution:

   This is due to what is called a "Black Hole" router. Mac OS and
   Windows 98 (and maybe other Microsoft OSs) send TCP packets with a
   requested segment size too big to fit into a PPPoE frame (MTU is
   1500 by default for Ethernet) and have the "do not fragment" bit
   set (default of TCP) and the Telco router is not sending ICMP
   "must fragment" back to the WWW site you are trying to load.
   (Alternatively, the router is sending the ICMP packet correctly,
   but the firewall at the WWW site is dropping it.) When the www
   server is sending you frames that do not fit into the PPPoE pipe
   the Telco router drops them on the floor and your page does not
   load (some pages/graphics do as they are smaller than a MSS). This
   seems to be the default of most Telco PPPoE configurations.

   One fix is to use regedit on your 95/98 system to add the
   following registry entry:

 HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Class\NetTrans\0000\MaxMTU

   It should be a string with a value 1436, as some ADSL routers are
   reported to be unable to deal with packets larger than this. This
   registry key has been changed to Tcpip\Parameters\Interfaces\ID
   for adapter\MTU in Windows 2000 and becomes a DWORD.

   Refer to the Microsoft Knowledge Base documents Q158474 - Windows
   TCPIP Registry Entries and Q120642 - TCPIP & NBT Configuration
   Parameters for Windows NT for more information on changing Windows
   MTU to work with a NAT router.

   Another regedit possibility under Windows 2000 to set the
   Tcpip\Parameters\Interfaces\ID for adapter\EnablePMTUBHDetect
   DWORD to 1 as mentioned in the Microsoft document 120642 mentioned
   above.

   Unfortunately, Mac OS does not provide an interface for changing
   TCP/IP settings. However, there are several commercial programs
   available that will allow users to customize TCP/IP settings.
   Mac OS NAT users should search for their MTU settings and enter
   1450 instead of 1500.

   The ppp(8) has an enable tcpmssfixup command that will
   automatically adjust the MSS to an appropriate value. This
   facility is enabled by default. If you are stuck with an older
   version of ppp(8), you may want to look at the net/tcpmssd port.

   14.26. None of this helps -- I am desperate! What can I do?

   If all else fails, send as much information as you can, including
   your config files, how you are starting ppp(8), the relevant parts
   of your log file and the output of the netstat -rn command (before
   and after connecting) to the FreeBSD general questions mailing
   list or the comp.unix.bsd.freebsd.misc news group, and someone
   should point you in the right direction.

     --------------------------------------------------------------

                    Chapter 15 Serial Communications

   This section answers common questions about serial communications
   with FreeBSD. PPP and SLIP are covered in the Networking section.

   15.1. How do I tell if FreeBSD found my serial ports?

   15.2. How do I tell if FreeBSD found my modem cards?

   15.3. How do I access the serial ports on FreeBSD?

   15.4. How do I enable support for a multiport serial card?

   15.5. Can FreeBSD handle multiport serial cards sharing IRQs?

   15.6. Can I set the default serial parameters for a port?

   15.7. How can I enable dialup logins on my modem?

   15.8. How can I connect a dumb terminal to my FreeBSD box?

   15.9. Why can I not run tip or cu?

   15.10. My stock Hayes modem is not supported -- what can I do?

   15.11. How am I expected to enter these AT commands?

   15.12. Why does the @ sign for the pn capability not work?

   15.13. How can I dial a phone number on the command line?

   15.14. Do I have to type in the bps rate every time I do that?

   15.15. How can I more easily access a number of hosts through a
   terminal server?

   15.16. Can tip try more than one line for each site?

   15.17. Why do I have to hit Ctrl+P twice to send Ctrl+P once?

   15.18. Why is everything I type suddenly in UPPER CASE?

   15.19. How can I do file transfers with tip?

   15.20. How can I run zmodem with tip?

   15.1. How do I tell if FreeBSD found my serial ports?

   As the FreeBSD kernel boots, it will probe for the serial ports in
   your system for which the kernel was configured. You can either
   watch your system closely for the messages it prints or run this
   command after your system is up and running:

 % dmesg | grep -E "^sio[0-9]"

   Here is some example output from the above command:

 sio0: <16550A-compatible COM port> port 0x3f8-0x3ff irq 4 flags 0x10 on acpi0
 sio0: type 16550A
 sio1: <16550A-compatible COM port> port 0x2f8-0x2ff irq 3 on acpi0
 sio1: type 16550A

   This shows two serial ports. The first is on IRQ 4, is using port
   address 0x3f8, and has a 16550A-type UART chip. The second uses
   the same kind of chip but is on IRQ 3 and is at port address
   0x2f8. Internal modem cards are treated just like serial ports --
   except that they always have a modem "attached" to the port.

   The GENERIC kernel includes support for two serial ports using the
   same IRQ and port address settings in the above example. If these
   settings are not right for your system, or if you have added modem
   cards or have more serial ports than your kernel is configured
   for, just reconfigure your kernel. See section about building a
   kernel for more details.

   15.2. How do I tell if FreeBSD found my modem cards?

   Refer to the answer to the previous question.

   15.3. How do I access the serial ports on FreeBSD?

   The third serial port, sio2 (see sio(4), known as COM3 in DOS), is
   on /dev/cuad2 for dial-out devices, and on /dev/ttyd2 for dial-in
   devices. What is the difference between these two classes of
   devices?

   You use ttydX for dial-ins. When opening /dev/ttydX in blocking
   mode, a process will wait for the corresponding cuadX device to
   become inactive, and then wait for the carrier detect line to go
   active. When you open the cuadX device, it makes sure the serial
   port is not already in use by the ttydX device. If the port is
   available, it "steals" it from the ttydX device. Also, the cuadX
   device does not care about carrier detect. With this scheme and an
   auto-answer modem, you can have remote users log in and you can
   still dial out with the same modem and the system will take care
   of all the conflicts.

   15.4. How do I enable support for a multiport serial card?

   Again, the section on kernel configuration provides information
   about configuring your kernel. For a multiport serial card, place
   an sio(4) line for each serial port on the card in the
   device.hints(5) file. But place the IRQ specifiers on only one of
   the entries. All of the ports on the card should share one IRQ.
   For consistency, use the last serial port to specify the IRQ.
   Also, specify the following option in the kernel configuration
   file:

 options COM_MULTIPORT

   The following /boot/device.hints example is for an AST 4-port
   serial card on IRQ 12:

 hint.sio.4.at="isa"
 hint.sio.4.port="0x2a0"
 hint.sio.4.flags="0x701"
 hint.sio.5.at="isa"
 hint.sio.5.port="0x2a8"
 hint.sio.5.flags="0x701"
 hint.sio.6.at="isa"
 hint.sio.6.port="0x2b0"
 hint.sio.6.flags="0x701"
 hint.sio.7.at="isa"
 hint.sio.7.port="0x2b8"
 hint.sio.7.flags="0x701"
 hint.sio.7.irq="12"

   The flags indicate that the master port has minor number 7
   (0x700), and all the ports share an IRQ (0x001).

   15.5. Can FreeBSD handle multiport serial cards sharing IRQs?

   Not yet. You will have to use a different IRQ for each card.

   15.6. Can I set the default serial parameters for a port?

   See the Serial Communications section in the FreeBSD Handbook.

   15.7. How can I enable dialup logins on my modem?

   Please read the section about Dial-in Services in the FreeBSD
   Handbook.

   15.8. How can I connect a dumb terminal to my FreeBSD box?

   You can find this information in the Terminals section of the
   FreeBSD Handbook.

   15.9. Why can I not run tip or cu?

   On your system, the programs tip(1) and cu(1) can only access the
   /var/spool/lock directory via user uucp and group dialer. You can
   use the group dialer to control who has access to your modem or
   remote systems. Just add yourself to group dialer.

   Alternatively, you can let everyone on your system run tip(1) and
   cu(1) by typing:

 # chmod 4511 /usr/bin/cu
 # chmod 4511 /usr/bin/tip

   15.10. My stock Hayes modem is not supported -- what can I do?

   See this answer in the FreeBSD Handbook.

   15.11. How am I expected to enter these AT commands?

   See this answer in the FreeBSD Handbook.

   15.12. Why does the @ sign for the pn capability not work?

   See this answer in the FreeBSD Handbook.

   15.13. How can I dial a phone number on the command line?

   See this answer in the FreeBSD Handbook.

   15.14. Do I have to type in the bps rate every time I do that?

   See this answer in the FreeBSD Handbook.

   15.15. How can I more easily access a number of hosts through a
   terminal server?

   See this answer in the FreeBSD Handbook.

   15.16. Can tip try more than one line for each site?

   See this answer in the FreeBSD Handbook.

   15.17. Why do I have to hit Ctrl+P twice to send Ctrl+P once?

   See this answer in the FreeBSD Handbook.

   15.18. Why is everything I type suddenly in UPPER CASE?

   See this answer in the FreeBSD Handbook.

   15.19. How can I do file transfers with tip?

   See this answer in the FreeBSD Handbook.

   15.20. How can I run zmodem with tip?

   See this answer in the FreeBSD Handbook.

     --------------------------------------------------------------

                   Chapter 16 Miscellaneous Questions

   16.1. FreeBSD uses far more swap space than Linux. Why?

   16.2. Why does top show very little free memory even when I have
   very few programs running?

   16.3. Why will chmod not change the permissions on symlinks?

   16.4. Can I run DOS binaries under FreeBSD?

   16.5. What do I need to do to translate a FreeBSD document into my
   native language?

   16.6. Why does my email to any address at FreeBSD.org bounce?

   16.7. Where can I find a free FreeBSD account?

   16.8. What is sup, and how do I use it?

   16.9. What is the cute little red guy's name?

   16.10. Can I use the BSD daemon image?

   16.11. Do you have any BSD daemon images I could use?

   16.12. I have seen an acronym or other term on the mailing lists
   and I do not understand what it means. Where should I look?

   16.13. Why should I care what color the bikeshed is?

   16.1. FreeBSD uses far more swap space than Linux. Why?

   FreeBSD only appears to use more swap than Linux. In actual fact,
   it does not. The main difference between FreeBSD and Linux in this
   regard is that FreeBSD will proactively move entirely idle, unused
   pages of main memory into swap in order to make more main memory
   available for active use. Linux tends to only move pages to swap
   as a last resort. The perceived heavier use of swap is balanced by
   the more efficient use of main memory.

   Note that while FreeBSD is proactive in this regard, it does not
   arbitrarily decide to swap pages when the system is truly idle.
   Thus you will not find your system all paged out when you get up
   in the morning after leaving it idle overnight.

   16.2. Why does top show very little free memory even when I have
   very few programs running?

   The simple answer is that free memory is wasted memory. Any memory
   that your programs do not actively allocate is used within the
   FreeBSD kernel as disk cache. The values shown by top(1) labeled
   as Inact, Cache, and Buf are all cached data at different aging
   levels. This cached data means the system does not have to access
   a slow disk again for data it has accessed recently, thus
   increasing overall performance. In general, a low value shown for
   Free memory in top(1) is good, provided it is not very low.

   16.3. Why will chmod not change the permissions on symlinks?

   Symlinks do not have permissions, and by default, chmod(1) will
   not follow symlinks to change the permissions on the target file.
   So if you have a file, foo, and a symlink to that file, bar, then
   this command will always succeed.

 % chmod g-w bar

   However, the permissions on foo will not have changed.

   You have to use either -H or -L together with the -R option to
   make this work. See the chmod(1) and symlink(7) manual pages for
   more info.

     Warning: The -R option does a recursive chmod(1). Be careful
     about specifying directories or symlinks to directories to
     chmod(1). If you want to change the permissions of a directory
     referenced by a symlink, use chmod(1) without any options and
     follow the symlink with a trailing slash (/). For example, if
     foo is a symlink to directory bar, and you want to change the
     permissions of foo (actually bar), you would do something like:

 % chmod 555 foo/

     With the trailing slash, chmod(1) will follow the symlink, foo,
     to change the permissions of the directory, bar.

   16.4. Can I run DOS binaries under FreeBSD?

   Yes, you can use emulators/doscmd, a DOS emulation program,
   available in the FreeBSD Ports Collection.

   If doscmd will not suffice, the add-on utility emulators/pcemu
   emulates an 8088 and enough BIOS services to run many DOS text
   mode applications. It requires the X Window System.

   You may also try emulators/dosbox from the FreeBSD Ports
   Collection. The main focus of this application is emulating old
   DOS games using the local file system for files.

   16.5. What do I need to do to translate a FreeBSD document into my
   native language?

   See the Translation FAQ in the FreeBSD Documentation Project
   Primer.

   16.6. Why does my email to any address at FreeBSD.org bounce?

   The FreeBSD.org mail system implements some of the stricter
   Postfix checks on incoming mail and rejects mail that is either
   misconfigured or is potential spam. Your mail might bounce for one
   of the following reasons:

     * The email is being sent from a known spam domain or IP block.

       The FreeBSD mail servers reject email from known spam sources.
       If you have service through a company or domain who generates
       or relays spam, please switch to a service provider who does
       not.

     * The body of the email only contains HTML.

       Mail should be sent in plain text only. Please configure your
       mail user agent to send plain text.

     * The mailer at FreeBSD.org cannot resolve the IP address of the
       connecting host back to a symbolic name.

       Working reverse DNS is a standard requirement for accepting
       mail from a host. Set up reverse DNS for your mail server's IP
       address. Many home services (DSL, cable, dialup, etc.) will
       not give you this option. In this case, relay your email
       through your service provider's mail server.

     * The hostname given in the EHLO/HELO part of the SMTP exchange
       cannot be resolved to an IP address.

       A fully qualified, resolvable host name is necessary in this
       part of the SMTP dialogue before mail will be accepted. If you
       do not have a host name that is registered in the DNS, then
       you should use your service provider's mail server to relay
       your mail.

     * Your message had a message ID ending with the string
       "localhost".

       Some mail user agents generate bad message IDs which will not
       be accepted. You will need to persuade your mail user agent to
       generate a valid message ID or else configure your mail
       transfer agent to rewrite them.

   16.7. Where can I find a free FreeBSD account?

   While FreeBSD does not provide open access to any of their
   servers, others do provide open access UNIX systems. The charge
   varies and limited services may be available.

   Arbornet, Inc, also known as M-Net, has been providing open access
   to UNIX systems since 1983. Starting on an Altos running System
   III, the site switched to BSD/OS in 1991. In June of 2000, the
   site switched again to FreeBSD. M-Net can be accessed via telnet
   and SSH and provides basic access to the entire FreeBSD software
   suite. However, network access is limited to members and patrons
   who donate to the system, which is run as a non-profit
   organization. M-Net also provides an bulletin board system and
   interactive chat.

   Grex provides a site very similar to M-Net including the same
   bulletin board and interactive chat software. However, the machine
   is a Sun 4M and is running SunOS.

   16.8. What is sup, and how do I use it?

   SUP stands for Software Update Protocol, and was developed by CMU
   for keeping their development trees in sync. It was used to keep
   remote sites in sync with the Project's central development
   sources.

   SUP is not bandwidth friendly, and has been retired. The current
   recommended method to keep your sources up to date is CVSup

   16.9. What is the cute little red guy's name?

   He does not have one, and is just called "the BSD daemon". If you
   insist upon using a name, call him "beastie". Note that "beastie"
   is pronounced "BSD".

   You can learn more about the BSD daemon on his home page.

   16.10. Can I use the BSD daemon image?

   Perhaps. The BSD daemon is copyrighted by Marshall Kirk McKusick.
   You will want to check his Statement on the Use of the BSD Daemon
   Figure for detailed usage terms.

   In summary, you are free to use the image in a tasteful manner,
   for personal use, so long as appropriate credit is given. If you
   want to use him commercially, you must contact Kirk McKusick
   <mckusick@FreeBSD.org>. More details are available on the BSD
   Daemon's home page.

   16.11. Do you have any BSD daemon images I could use?

   You will find eps and Xfig drawings under
   /usr/share/examples/BSD_daemon/.

   16.12. I have seen an acronym or other term on the mailing lists
   and I do not understand what it means. Where should I look?

   Please see the FreeBSD Glossary.

   16.13. Why should I care what color the bikeshed is?

   The really, really short answer is that you should not. The
   somewhat longer answer is that just because you are capable of
   building a bikeshed does not mean you should stop others from
   building one just because you do not like the color they plan to
   paint it. This is a metaphor indicating that you need not argue
   about every little feature just because you know enough to do so.
   Some people have commented that the amount of noise generated by a
   change is inversely proportional to the complexity of the change.

   The longer and more complete answer is that after a very long
   argument about whether sleep(1) should take fractional second
   arguments, Poul-Henning Kamp <phk@FreeBSD.org> posted a long
   message entitled "A bike shed (any color will do) on greener
   grass...". The appropriate portions of that message are quoted
   below.

     "What is it about this bike shed?" Some of you have asked me.    
                                                                    
     It is a long story, or rather it is an old story, but it is    
     quite short actually. C. Northcote Parkinson wrote a book in   
     the early 1960s, called "Parkinson's Law", which contains a    
     lot of insight into the dynamics of management.                
                                                                    
     [snip a bit of commentary on the book]                         
                                                                    
     In the specific example involving the bike shed, the other     
     vital component is an atomic power-plant, I guess that         
     illustrates the age of the book.                               
                                                                    
     Parkinson shows how you can go into the board of directors and 
     get approval for building a multi-million or even billion      
     dollar atomic power plant, but if you want to build a bike     
     shed you will be tangled up in endless discussions.            
                                                                    
     Parkinson explains that this is because an atomic plant is so  
     vast, so expensive and so complicated that people cannot grasp 
     it, and rather than try, they fall back on the assumption that 
     somebody else checked all the details before it got this far.  
     Richard P. Feynmann gives a couple of interesting, and very    
     much to the point, examples relating to Los Alamos in his      
     books.                                                         
                                                                    
     A bike shed on the other hand. Anyone can build one of those   
     over a weekend, and still have time to watch the game on TV.   
     So no matter how well prepared, no matter how reasonable you   
     are with your proposal, somebody will seize the chance to show 
     that he is doing his job, that he is paying attention, that he 
     is here.                                                       
                                                                    
     In Denmark we call it "setting your fingerprint". It is about  
     personal pride and prestige, it is about being able to point   
     somewhere and say "There! I did that." It is a strong trait in 
     politicians, but present in most people given the chance. Just 
     think about footsteps in wet cement.                           
          --Poul-Henning Kamp <phk@FreeBSD.org> on freebsd-hackers,   
                                                    October 2, 1999 

     --------------------------------------------------------------

                     Chapter 17 The FreeBSD Funnies

   17.1. How cool is FreeBSD?

   17.2. Who is scratching in my memory banks??

   17.3. How many FreeBSD hackers does it take to change a lightbulb?

   17.4. Where does data written to /dev/null go?

   17.1. How cool is FreeBSD?

   Q. Has anyone done any temperature testing while running FreeBSD?
   I know Linux runs cooler than DOS, but have never seen a mention
   of FreeBSD. It seems to run really hot.

   A. No, but we have done numerous taste tests on blindfolded
   volunteers who have also had 250 micrograms of LSD-25 administered
   beforehand. 35% of the volunteers said that FreeBSD tasted sort of
   orange, whereas Linux tasted like purple haze. Neither group
   mentioned any significant variances in temperature. We eventually
   had to throw the results of this survey out entirely anyway when
   we found that too many volunteers were wandering out of the room
   during the tests, thus skewing the results. We think most of the
   volunteers are at Apple now, working on their new "scratch and
   sniff" GUI. It is a funny old business we are in!

   Seriously, both FreeBSD and Linux use the HLT (halt) instruction
   when the system is idle thus lowering its energy consumption and
   therefore the heat it generates. Also if you have APM (advanced
   power management) configured, then FreeBSD can also put the CPU
   into a low power mode.

   17.2. Who is scratching in my memory banks??

   Q. Is there anything "odd" that FreeBSD does when compiling the
   kernel which would cause the memory to make a scratchy sound? When
   compiling (and for a brief moment after recognizing the floppy
   drive upon startup, as well), a strange scratchy sound emanates
   from what appears to be the memory banks.

   A. Yes! You will see frequent references to "daemons" in the BSD
   documentation, and what most people do not know is that this
   refers to genuine, non-corporeal entities that now possess your
   computer. The scratchy sound coming from your memory is actually
   high-pitched whispering exchanged among the daemons as they best
   decide how to deal with various system administration tasks.

   If the noise gets to you, a good fdisk /mbr from DOS will get rid
   of them, but do not be surprised if they react adversely and try
   to stop you. In fact, if at any point during the exercise you hear
   the satanic voice of Bill Gates coming from the built-in speaker,
   take off running and do not ever look back! Freed from the
   counterbalancing influence of the BSD daemons, the twin demons of
   DOS and Windows are often able to re-assert total control over
   your machine to the eternal damnation of your soul. Now that you
   know, given a choice you would probably prefer to get used to the
   scratchy noises, no?

   17.3. How many FreeBSD hackers does it take to change a lightbulb?

   One thousand, one hundred and sixty-nine:

   Twenty-three to complain to -CURRENT about the lights being out;

   Four to claim that it is a configuration problem, and that such
   matters really belong on -questions;

   Three to submit PRs about it, one of which is misfiled under doc
   and consists only of "it's dark";

   One to commit an untested lightbulb which breaks buildworld, then
   back it out five minutes later;

   Eight to flame the PR originators for not including patches in
   their PRs;

   Five to complain about buildworld being broken;

   Thirty-one to answer that it works for them, and they must have
   cvsupped at a bad time;

   One to post a patch for a new lightbulb to -hackers;

   One to complain that he had patches for this three years ago, but
   when he sent them to -CURRENT they were just ignored, and he has
   had bad experiences with the PR system; besides, the proposed new
   lightbulb is non-reflexive;

   Thirty-seven to scream that lightbulbs do not belong in the base
   system, that committers have no right to do things like this
   without consulting the Community, and WHAT IS -CORE DOING ABOUT
   IT!?

   Two hundred to complain about the color of the bicycle shed;

   Three to point out that the patch breaks style(9);

   Seventeen to complain that the proposed new lightbulb is under
   GPL;

   Five hundred and eighty-six to engage in a flame war about the
   comparative advantages of the GPL, the BSD license, the MIT
   license, the NPL, and the personal hygiene of unnamed FSF
   founders;

   Seven to move various portions of the thread to -chat and
   -advocacy;

   One to commit the suggested lightbulb, even though it shines
   dimmer than the old one;

   Two to back it out with a furious flame of a commit message,
   arguing that FreeBSD is better off in the dark than with a dim
   lightbulb;

   Forty-six to argue vociferously about the backing out of the dim
   lightbulb and demanding a statement from -core;

   Eleven to request a smaller lightbulb so it will fit their
   Tamagotchi if we ever decide to port FreeBSD to that platform;

   Seventy-three to complain about the SNR on -hackers and -chat and
   unsubscribe in protest;

   Thirteen to post "unsubscribe", "How do I unsubscribe?", or
   "Please remove me from the list", followed by the usual footer;

   One to commit a working lightbulb while everybody is too busy
   flaming everybody else to notice;

   Thirty-one to point out that the new lightbulb would shine 0.364%
   brighter if compiled with TenDRA (although it will have to be
   reshaped into a cube), and that FreeBSD should therefore switch to
   TenDRA instead of GCC;

   One to complain that the new lightbulb lacks fairings;

   Nine (including the PR originators) to ask "what is MFC?";

   Fifty-seven to complain about the lights being out two weeks after
   the bulb has been changed.

   Nik Clayton <nik@FreeBSD.org> adds:

   I was laughing quite hard at this.

   And then I thought, "Hang on, shouldn't there be '1 to document
   it.' in that list somewhere?"

   And then I was enlightened :-)

   Thomas Abthorpe <tabthorpe@FreeBSD.org> says: "None, real FreeBSD
   hackers are not afraid of the dark!"

   17.4. Where does data written to /dev/null go?

   It goes into a special data sink in the CPU where it is converted
   to heat which is vented through the heatsink / fan assembly. This
   is why CPU cooling is increasingly important; as people get used
   to faster processors, they become careless with their data and
   more and more of it ends up in /dev/null, overheating their CPUs.
   If you delete /dev/null (which effectively disables the CPU data
   sink) your CPU may run cooler but your system will quickly become
   constipated with all that excess data and start to behave
   erratically. If you have a fast network connection you can cool
   down your CPU by reading data out of /dev/random and sending it
   off somewhere; however you run the risk of overheating your
   network connection and / or angering your ISP, as most of the data
   will end up getting converted to heat by their equipment, but they
   generally have good cooling, so if you do not overdo it you should
   be OK.

   Paul Robinson adds:

   There are other methods. As every good sysadmin knows, it is part
   of standard practice to send data to the screen of interesting
   variety to keep all the pixies that make up your picture happy.
   Screen pixies (commonly mis-typed or re-named as "pixels") are
   categorized by the type of hat they wear (red, green or blue) and
   will hide or appear (thereby showing the color of their hat)
   whenever they receive a little piece of food. Video cards turn
   data into pixie-food, and then send them to the pixies -- the more
   expensive the card, the better the food, so the better behaved the
   pixies are. They also need constant stimulation -- this is why
   screen savers exist.

   To take your suggestions further, you could just throw the random
   data to console, thereby letting the pixies consume it. This
   causes no heat to be produced at all, keeps the pixies happy and
   gets rid of your data quite quickly, even if it does make things
   look a bit messy on your screen.

   Incidentally, as an ex-admin of a large ISP who experienced many
   problems attempting to maintain a stable temperature in a server
   room, I would strongly discourage people sending the data they do
   not want out to the network. The fairies who do the packet
   switching and routing get annoyed by it as well.

     --------------------------------------------------------------

                       Chapter 18 Advanced Topics

   18.1. How can I learn more about FreeBSD's internals?

   18.2. How can I contribute to FreeBSD?

   18.3. What are snapshots and releases?

   18.4. How do I make my own custom release?

   18.5. Why does make world clobber my existing installed binaries?

   18.6. Why isn't cvsup.FreeBSD.org a round robin DNS entry to share
   the load amongst the various CVSup servers?

   18.7. Can I follow -CURRENT with limited Internet access?

   18.8. How did you split the distribution into 1392 KB files?

   18.9. I have written a kernel extension, who do I send it to?

   18.10. How are Plug N Play ISA cards detected and initialized?

   18.11. Can you assign a major number for a device driver I have
   written?

   18.12. What about alternative layout policies for directories?

   18.13. How can I make the most of the data I see when my kernel
   panics?

   18.14. Why has dlsym() stopped working for ELF executables?

   18.15. How can I increase or reduce the kernel address space on
   i386?

   18.1. How can I learn more about FreeBSD's internals?

   At this time, there is only one book on FreeBSD-specific OS
   internals, namely "The Design and Implementation of the FreeBSD
   Operating System" by Marshall Kirk McKusick and George V.
   Neville-Neil, ISBN 0-201-70245-2, which focuses on version 5.X of
   FreeBSD.

   Additionally, much general UNIX knowledge is directly applicable
   to FreeBSD.

   For a list of relevant books, please check the Handbook's
   Operating System Internals Bibliography.

   18.2. How can I contribute to FreeBSD?

   Please see the article on Contributing to FreeBSD for specific
   advice on how to do this. Assistance is more than welcome!

   18.3. What are snapshots and releases?

   There are currently three active/semi-active branches in the
   FreeBSD CVS Repository. (Earlier branches are only changed very
   rarely, which is why there are only three active branches of
   development):

     * RELENG_6 AKA 6-STABLE

     * RELENG_7 AKA 7-STABLE

     * HEAD AKA -CURRENT AKA 8-CURRENT

   HEAD is not an actual branch tag, like the other two; it is simply
   a symbolic constant for "the current, non-branched development
   stream" which we simply refer to as -CURRENT.

   Right now, -CURRENT is the 8.X development stream; the 6-STABLE
   branch, RELENG_6, forked off from -CURRENT in November 2005, and
   the 7-STABLE branch, RELENG_7, forked off from -CURRENT in
   February 2008.

   18.4. How do I make my own custom release?

   Please see the Release Engineering article.

   18.5. Why does make world clobber my existing installed binaries?

   Yes, this is the general idea; as its name might suggest, make
   world rebuilds every system binary from scratch, so you can be
   certain of having a clean and consistent environment at the end
   (which is why it takes so long).

   If the environment variable DESTDIR is defined while running make
   world or make install, the newly-created binaries will be
   deposited in a directory tree identical to the installed one,
   rooted at ${DESTDIR}. Some random combination of shared libraries
   modifications and program rebuilds can cause this to fail in make
   world however.

   18.6. Why isn't cvsup.FreeBSD.org a round robin DNS entry to share
   the load amongst the various CVSup servers?

   While CVSup mirrors update from the master CVSup server hourly,
   this update might happen at any time during the hour. This means
   that some servers have newer code than others, even though all
   servers have code that is less than an hour old. If
   cvsup.FreeBSD.org was a round robin DNS entry that simply
   redirected users to a random CVSup server, running CVSup twice in
   a row could download code older than the code already on the
   system.

   18.7. Can I follow -CURRENT with limited Internet access?

   Yes, you can do this without downloading the whole source tree by
   using the CTM facility.

   18.8. How did you split the distribution into 1392 KB files?

   Newer BSD based systems have a -b option to split(1) that allows
   them to split files on arbitrary byte boundaries.

   Here is an example from /usr/src/release/Makefile.

 ZIPNSPLIT=              gzip --no-name -9 -c | split -b 1392k -

   18.9. I have written a kernel extension, who do I send it to?

   Please take a look at the article on Contributing to FreeBSD to
   learn how to submit code.

   And thanks for the thought!

   18.10. How are Plug N Play ISA cards detected and initialized?

   By: Frank Durda IV <uhclem@nemesis.lonestar.org>

   In a nutshell, there a few I/O ports that all of the PnP boards
   respond to when the host asks if anyone is out there. So when the
   PnP probe routine starts, it asks if there are any PnP boards
   present, and all the PnP boards respond with their model # to a
   I/O read of the same port, so the probe routine gets a wired-OR
   "yes" to that question. At least one bit will be on in that reply.
   Then the probe code is able to cause boards with board model IDs
   (assigned by Microsoft/Intel) lower than X to go "off-line". It
   then looks to see if any boards are still responding to the query.
   If the answer was 0, then there are no boards with IDs above X.
   Probe will then ask for boards below X. Finally, probe requests
   boards greater than X - (limit / 4) to go off-line. It then
   repeats this query. By repeating this semi-binary search of
   IDs-in-range enough times, the probing code will eventually
   identify all PnP boards present in a given machine with a number
   of iterations that is much lower than what 264 would take.

   The IDs are two 32-bit fields (hence 264) + 8-bit checksum. The
   first 32 bits are a vendor identifier. They never come out and say
   it, but it appears to be assumed that different types of boards
   from the same vendor could have different 32-bit vendor IDs. The
   idea of needing 32 bits just for unique manufacturers is a bit
   excessive.

   The lower 32 bits are a serial #, or something else that makes
   this one board unique. The vendor must never produce a second
   board that has the same lower 32 bits unless the upper 32 bits are
   also different. So you can have multiple boards of the same type
   in the machine and the full 64 bits will still be unique.

   The 32-bit groups can never be all zero. This allows the wired-OR
   to show non-zero bits during the initial binary search.

   Once the system has identified all the board IDs present, it will
   reactivate each board, one at a time (via the same I/O ports), and
   find out what resources the given board needs, what interrupt
   choices are available, etc. A scan is made over all the boards to
   collect this information.

   This info is then combined with info from any ECU files on the
   hard disk or wired into the MLB BIOS. The ECU and BIOS PnP support
   for hardware on the MLB is usually synthetic, and the peripherals
   do not really do genuine PnP. However by examining the BIOS info
   plus the ECU info, the probe routines can cause the devices that
   are PnP to avoid those devices the probe code cannot relocate.

   Then the PnP devices are visited once more and given their I/O,
   DMA, IRQ and Memory-map address assignments. The devices will then
   appear at those locations and remain there until the next reboot,
   although there is nothing that says you cannot move them around
   whenever you want.

   There is a lot of oversimplification above, but you should get the
   general idea.

   Microsoft took over some of the primary printer status ports to do
   PnP, on the logic that no boards decoded those addresses for the
   opposing I/O cycles. I found a genuine IBM printer board that did
   decode writes of the status port during the early PnP proposal
   review period, but Microsoft said "tough". So they do a write to
   the printer status port for setting addresses, plus that use that
   address + 0x800, and a third I/O port for reading that can be
   located anywhere between 0x200 and 0x3ff.

   18.11. Can you assign a major number for a device driver I have
   written?

   FreeBSD releases after February 2003 has a facility for
   dynamically and automatically allocating major numbers for device
   drivers at runtime (see devfs(5)), so there is no need for this.

   18.12. What about alternative layout policies for directories?

   In answer to the question of alternative layout policies for
   directories, the scheme that is currently in use is unchanged from
   what I wrote in 1983. I wrote that policy for the original fast
   file system, and never revisited it. It works well at keeping
   cylinder groups from filling up. As several of you have noted, it
   works poorly for find. Most file systems are created from archives
   that were created by a depth first search (aka ftw). These
   directories end up being striped across the cylinder groups thus
   creating a worst possible scenario for future depth first
   searches. If one knew the total number of directories to be
   created, the solution would be to create (total / fs_ncg) per
   cylinder group before moving on. Obviously, one would have to
   create some heuristic to guess at this number. Even using a small
   fixed number like say 10 would make an order of magnitude
   improvement. To differentiate restores from normal operation (when
   the current algorithm is probably more sensible), you could use
   the clustering of up to 10 if they were all done within a ten
   second window. Anyway, my conclusion is that this is an area ripe
   for experimentation.

   Kirk McKusick <mckusick@FreeBSD.org>, September 1998

   18.13. How can I make the most of the data I see when my kernel
   panics?

   Here is typical kernel panic:

 Fatal trap 12: page fault while in kernel mode
 fault virtual address   = 0x40
 fault code              = supervisor read, page not present
 instruction pointer     = 0x8:0xf014a7e5
 stack pointer           = 0x10:0xf4ed6f24
 frame pointer           = 0x10:0xf4ed6f28
 code segment            = base 0x0, limit 0xfffff, type 0x1b
                         = DPL 0, pres 1, def32 1, gran 1
 processor eflags        = interrupt enabled, resume, IOPL = 0
 current process         = 80 (mount)
 interrupt mask          =
 trap number             = 12
 panic: page fault

   When you see a message like this, it is not enough to just
   reproduce it and send it in. The instruction pointer value is
   important; unfortunately, it is also configuration dependent. In
   other words, the value varies depending on the exact kernel image
   that you are using. If you are using a GENERIC kernel image from
   one of the snapshots, then it is possible for somebody else to
   track down the offending function, but if you are running a custom
   kernel then only you can tell us where the fault occurred.

   What you should do is this:

    1. Write down the instruction pointer value. Note that the 0x8:
       part at the beginning is not significant in this case: it is
       the 0xf0xxxxxx part that we want.

    2. When the system reboots, do the following:

 % nm -n kernel.that.caused.the.panic | grep f0xxxxxx

       where f0xxxxxx is the instruction pointer value. The odds are
       you will not get an exact match since the symbols in the
       kernel symbol table are for the entry points of functions and
       the instruction pointer address will be somewhere inside a
       function, not at the start. If you do not get an exact match,
       omit the last digit from the instruction pointer value and try
       again, i.e.:

 % nm -n kernel.that.caused.the.panic | grep f0xxxxx

       If that does not yield any results, chop off another digit.
       Repeat until you get some sort of output. The result will be a
       possible list of functions which caused the panic. This is a
       less than exact mechanism for tracking down the point of
       failure, but it is better than nothing.

   However, the best way to track down the cause of a panic is by
   capturing a crash dump, then using kgdb(1) to generate a stack
   trace on the crash dump.

   In any case, the method is this:

    1. Make sure that the following line is included in your kernel
       configuration file (/usr/src/sys/arch/conf/MYKERNEL):

 makeoptions     DEBUG=-g          # Build kernel with gdb(1) debug symbols

    2. Change to the /usr/src directory:

 # cd /usr/src

    3. Compile the kernel:

 # make buildkernel KERNCONF=MYKERNEL

    4. Wait for make(1) to finish compiling.

    5. # make installkernel KERNCONF=MYKERNEL

    6. Reboot.

     Note: If you do not use the KERNCONF make variable a GENERIC
     kernel will be built and installed.

   The make(1) process will have built two kernels.
   /usr/obj/usr/src/sys/MYKERNEL/kernel and
   /usr/obj/usr/src/sys/MYKERNEL/kernel.debug. kernel was installed
   as /boot/kernel/kernel, while kernel.debug can be used as the
   source of debugging symbols for kgdb(1).

   To make sure you capture a crash dump, you need edit /etc/rc.conf
   and set dumpdev to point to your swap partition (or AUTO). This
   will cause the rc(8) scripts to use the dumpon(8) command to
   enable crash dumps. You can also run dumpon(8) manually. After a
   panic, the crash dump can be recovered using savecore(8); if
   dumpdev is set in /etc/rc.conf, the rc(8) scripts will run
   savecore(8) automatically and put the crash dump in /var/crash.

     Note: FreeBSD crash dumps are usually the same size as the
     physical RAM size of your machine. That is, if you have 512 MB
     of RAM, you will get a 512 MB crash dump. Therefore you must
     make sure there is enough space in /var/crash to hold the dump.
     Alternatively, you run savecore(8) manually and have it recover
     the crash dump to another directory where you have more room. It
     is possible to limit the size of the crash dump by using options
     MAXMEM=N where N is the size of kernel's memory usage in KBs.
     For example, if you have 1 GB of RAM, you can limit the kernel's
     memory usage to 128 MB by this way, so that your crash dump size
     will be 128 MB instead of 1 GB.

   Once you have recovered the crash dump, you can get a stack trace
   with kgdb(1) as follows:

 % kgdb /usr/obj/usr/src/sys/MYKERNEL/kernel.debug /var/crash/vmcore.0
 (kgdb) backtrace

   Note that there may be several screens worth of information;
   ideally you should use script(1) to capture all of them. Using the
   unstripped kernel image with all the debug symbols should show the
   exact line of kernel source code where the panic occurred. Usually
   you have to read the stack trace from the bottom up in order to
   trace the exact sequence of events that lead to the crash. You can
   also use kgdb(1) to print out the contents of various variables or
   structures in order to examine the system state at the time of the
   crash.

     Tip: Now, if you are really insane and have a second computer,
     you can also configure kgdb(1) to do remote debugging such that
     you can use kgdb(1) on one system to debug the kernel on another
     system, including setting breakpoints, single-stepping through
     the kernel code, just like you can do with a normal user-mode
     program.

     Note: If you have DDB enabled and the kernel drops into the
     debugger, you can force a panic (and a crash dump) just by
     typing panic at the ddb prompt. It may stop in the debugger
     again during the panic phase. If it does, type continue and it
     will finish the crash dump.

   18.14. Why has dlsym() stopped working for ELF executables?

   The ELF toolchain does not, by default, make the symbols defined
   in an executable visible to the dynamic linker. Consequently
   dlsym() searches on handles obtained from calls to dlopen(NULL,
   flags) will fail to find such symbols.

   If you want to search, using dlsym(), for symbols present in the
   main executable of a process, you need to link the executable
   using the --export-dynamic option to the ELF linker (ld(1)).

   18.15. How can I increase or reduce the kernel address space on
   i386?

   By default, the kernel address space is 1 GB (2 GB for PAE) for
   i386. If you run a network-intensive server (e.g. a large FTP or
   HTTP server), or you want to use ZFS, you might find that is not
   enough.

   Add the following line to your kernel configuration file to
   increase available space and rebuild your kernel:

 options KVA_PAGES=N

   To find the correct value of N, divide the desired address space
   size (in megabytes) by four. (For example, it is 512 for 2 GB.)

     --------------------------------------------------------------

                       Chapter 19 Acknowledgments

   This innocent little Frequently Asked Questions document has been
   written, rewritten, edited, folded, spindled, mutilated,
   eviscerated, contemplated, discombobulated, cogitated,
   regurgitated, rebuilt, castigated, and reinvigorated over the last
   decade, by a cast of hundreds if not thousands. Repeatedly.

   We wish to thank every one of the people responsible, and we
   encourage you to to join them in making this FAQ even better.

     --------------------------------------------------------------

                              Bibliography

   FreeBSD Unleashed, Michael Urban and Brian Tiemann, Sams, 1st
   edition, 992 pages, October 2001, ISBN 0-67232-206-4.

   4.4BSD System Manager's Manual, Computer Systems Research Group,
   University of California, Berkeley, O'Reilly and Associates, 1st
   edition, June 1994, 804 pages, ISBN 1-56592-080-5.

   4.4BSD User's Reference Manual, Computer Systems Research Group,
   University of California, Berkeley, O'Reilly and Associates, 1st
   edition, June 1994, 905 pages, ISBN 1-56592-075-9.

   4.4BSD User's Supplementary Documents, Computer Systems Research
   Group, University of California, Berkeley, O'Reilly and
   Associates, 1st edition, June 1994, 712 pages, ISBN 1-56592-076-7.

   4.4BSD Programmer's Reference Manual, Computer Systems Research
   Group, University of California, Berkeley, O'Reilly and
   Associates, 1st edition, June 1994, 866 pages, ISBN 1-56592-078-3.

   4.4BSD Programmer's Supplementary Documents, Computer Systems
   Research Group, University of California, Berkeley, O'Reilly and
   Associates, 1st edition, June 1994, 596 pages, ISBN 1-56592-079-1.

   The Design and Implementation of the 4.4BSD Operating System, M.
   K. McKusick, Kirk Marshall, Keith Bostic, Michael J Karels, and
   John Quarterman, Addison-Wesley, Reading, 1996, ISBN
   0-201-54979-4.

   The Design and Implementation of the FreeBSD Operating System, M.
   K. McKusick and George V. Neville-Neil, Addison-Wesley, Boston,
   2004, ISBN 0-201-70245-2.

   Unix System Administration Handbook, Evi Nemeth, Garth Snyder,
   Scott Seebass, Trent R. Hein, and John Quarterman, Prentice-Hall,
   3rd edition, 2000, ISBN 0-13-020601-6.

   The Complete FreeBSD, Greg Lehey, Walnut Creek, 3rd edition, June
   1999, 773 pages, ISBN 1-57176-246-9.

   The FreeBSD Handbook, FreeBSD Documentation Project, BSDi, 1st
   edition, November 1999, 489 pages, ISBN 1-57176-241-8.

   [McKusick et al, 1994] Berkeley Software Architecture Manual,
   4.4BSD Edition, M. K. McKusick, M. J. Karels, S. J. Leffler, W. N.
   Joy, and R. S. Faber, 5:1-42.

   FreeBSD for PC 98'ers (in Japanese), SHUWA System Co, LTD., ISBN
   4-87966-468-5 C3055 P2900E.

   FreeBSD (in Japanese), CUTT, ISBN 4-906391-22-2.

   Complete Introduction to FreeBSD (in Japanese), Shoeisha Co., Ltd,
   ISBN 4-88135-473-6 P3600E.

   Personal UNIX Starter Kit FreeBSD (in Japanese), ASCII, ISBN
   4-7561-1733-3 P3000E.

   FreeBSD Handbook (Japanese translation), ASCII, ISBN 4-7561-1580-2
   P3800E.

   FreeBSD mit Methode (in German), Computer und Literature
   Verlag/Vertrieb Hanser, 1998, ISBN 3-932311-31-0.

   FreeBSD install and Utilization Manual (in Japanese), Mainichi
   Communications Inc..

   Building Internet Server with FreeBSD (in Indonesia Language),
   Elex Media Komputindo, Onno W Purbo, Dodi Maryanto, Syahrial
   Hubbany, and Widjil Widodo.

   The FreeBSD Corporate Networker's Guide, Addison-Wesley.

   UNIX in a Nutshell, O'Reilly & Associates, Inc., 1990, ISBN
   093717520X.

   What You Need To Know When You Can't Find Your Unix System
   Administrator, O'Reilly & Associates, Inc., 1995, Linda Mui, ISBN
   1-56592-104-6.

   FreeBSD User's Reference Manual (Japanese translation), Mainichi
   Communications Inc., Jpman Project, Japan FreeBSD Users Group,
   1998, ISBN 4-8399-0088-4 P3800E.

   Online Guide for newcomers to the UNIX environment, Edinburgh
   University.

   DNS and BIND, O'Reilly & Associates, Inc, ISBN 1-56592-512-2, Paul
   Albitz Albitz and Cricket Liu, 1998, 3rd edition.

   Sendmail, O'Reilly & Associates, Inc, 1997, 2nd edition, Brian
   Costales, ISBN 1-56592-222-0.

   Essential System Administration, AEleen Frisch, 2nd edition,
   O'Reilly & Associates, 1995, ISBN 1-56592-127-5.

   TCP/IP Network Administration, Craig Hunt, 2nd edition, O'Reilly &
   Associates, Inc, 1997, ISBN 1-56592-322-7.

   Managing NFS and NIS, Hal Stern, O'Reilly & Associates, Inc, 1991,
   ISBN 0-937175-75-7.

   FreeBSD System Administration's Manual, Jpman Project, Japan
   FreeBSD Users Group, Mainichi Communications Inc., 1998, ISBN
   4-8399-0109-0 P3300E.

   X Window System Toolkit, Digital Press, Paul Asente, ISBN
   1-55558-051-3.

   C: A Reference Manual, Prentice Hall, 1995, 4th edition, Samuel P.
   Harbison and Guy L. Jr. Steele, ISBN 0-13-326224-3.

   The C Programming Language, Prentice Hall, 1998, Brian Kernighan
   and Dennis Ritchie, ISBN 0-13-110362-9.

   Porting UNIX Software, Greg Lehey, O'Reilly & Associates, Inc.,
   1995, ISBN 1-56592-126-7.

   The Standard C Library, Prentice Hall, 1992, P. J. Plauger, ISBN
   0-13-131509-9.

   Advanced Programming in the UNIX Environment, Addison-Wesley,
   1992, W. Richard Stevens, ISBN 0-201-56317-7.

   UNIX Network Programming, W. Richard Stevens, Prentice Hall, 1998,
   2nd edition, ISBN 0-13-490012-X.

   Writing Serial Drivers for UNIX, Bill Wells, December 1994, Dr.
   Dobb's Journal, pp68-71, pp97-99.

   UNIX System Architecture, Prentice-Hall, Inc, 1990, Prabhat K.
   Andleigh, ISBN 0-13-949843-5.

   Porting UNIX to the 386, William Jolitz, Dr. Dobb's Journal,
   January 1991-July 1992.

   TCP/IP Illustrated, Volume 1: The Protocols, W. Richard Stevens,
   Addison-Wesley, 1996, ISBN 0-201-63346-9.

   Unix Systems for Modern Architectures, Addison-Wesley, Curt
   Schimmel, 1994, ISBN 0-201-63338-8.

   TCP/IP Illustrated, Volume 3: TCP for Transactions, HTTP, NNTP and
   the UNIX Domain Protocols, Addison-Wesley, 1996, W. Richard
   Stevens, ISBN 0-201-63495-3.

   UNIX Internals -- The New Frontiers, Uresh Vahalia, Prentice Hall,
   1996, ISBN 0-13-101908-2.

   TCP/IP Illustrated, Volume 2: The Implementation, Gary R. Wright
   and W. Richard Stevens, 1995, Addison-Wesley, ISBN 0-201-63354-X.

   Firewalls and Internet Security: Repelling the Wily Hacker,
   William R. CHeswick and Steven M. Bellovin, Addison-Wesley, 1995,
   ISBN 0-201-63357-4.

   Practical UNIX Security, Simson Garfinkel and Gene Spafford, 1996,
   2nd edition, O'Reilly & Associates, Inc, ISBN 1-56592-148-8.

   PGP Pretty Good Privacy, Simson Garfinkel, O'Reilly & Associates,
   Inc, 1995, ISBN 1-56592-098-8.

   Pentium Processor System Architecture, Don Anderson and Tom
   Shanley, Addison-Wesley, 1995, 2nd edition, ISBN 0-201-40992-5.

   Programmer's Guide to the EGA, VGA, and Super VGA Cards, Richard
   F. Ferraro, 3rd edition, Addison-Wesley, 1995, ISBN 0-201-62490-7.

   80486 System Architecture, Tom Shanley, Addison-Wesley, 1995, 3rd
   edition, ISBN 0-201-40994-1.

   ISA System Architecture, Tom Shanley, Addison-Wesley, 3rd edition,
   1995, ISBN 0-201-40996-8.

   PCI System Architecture, Tom Shanley, Addison-Wesley, 1995, 3rd
   edition, ISBN 0-201-40993-3.

   The Undocumented PC, Frank Van Gilluwe, Addison-Wesley, 1994, ISBN
   0-201-62277-7.

   Bell System Technical Journal, Unix Time-Sharing System, American
   Telephone & Telegraph Company, July-August 1978, Vol 57, No 6,
   Part 2, ISSN0005-8580.

   Lion's Commentary on UNIX, John Lion, ITP Media Group, 1996, 6th
   edition, ISBN 1573980137.

   The New Hacker's Dictionary, Eric S. Raymond, MIT Press, 1996, 3rd
   edition, ISBN 0-262-68092-0.

   A quarter century of UNIX, Peter H. Salus, Addison-Wesley, 1994,
   ISBN 0-201-54777-5.

   The UNIX-HATERS Handbook, Steven Strassman, Daniel Weise, and
   Simon Garfinkel, IDG Books Worldwide, Inc, 1994, ISBN
   1-56884-203-1.

   Life with UNIX -- special edition, Don Libes and Sandy Ressler,
   Prentice-Hall, 1989, ISBN 0-13-536657-7.

   The BSD Family Tree, 1997.

   Absolute BSD, Michael Lucas, No Starch Press, June 2002, ISBN
   1-886411-74-3.

   The C/C++ Users Journal, R&D Publications Inc., ISSN 1075-2838.

   Sys Admin -- The Journal for UNIX System Administrators, Miller
   Freeman, Inc, ISSN 1061-2688.

  Notes

   [1] In an email from Keith Frechette <kfrechet@us.ibm.com>.        

     --------------------------------------------------------------

           This, and other documents, can be downloaded from
                ftp://ftp.FreeBSD.org/pub/FreeBSD/doc/.

 For questions about FreeBSD, read the documentation before contacting
                        <questions@FreeBSD.org>.
   For questions about this documentation, e-mail <doc@FreeBSD.org>.
