QUESTIONS
-----------

Q1 - I restore/save all files but dar reported some files have been ignored, what are those ignored files?
Q2 - Dar hangs when using it with pipes, why?
Q3 - Why, when I restore 1 file, dar report 3 files have been restored?
Q4 - I cannot find the binary package for my distro, where to look for?
Q5 - Why, when does dar report "ignored" files while I make a backup without filters?
Q6 - Can I use different filters between a full backup and a differential backup? Would not dar consider some file not included in the filter to be deleted?

ANSWERS
--------

A1 - When restoring/saving, all files are considered by default. But if you specify some files to restore or save, all other files are "ignored", this is the case when using -P -X -I or -g.

A2 - Dar can produce archive on its standard output, if you give '-' as basename. But it cannot read an archive from its standard input. To feed an archive to dar through pipes, you need dar_slave and two pipes. The first pipe transmits orders from dar to dar_slave that tell dar_slave the requested portion of the archive, the second pipe goes the other way and carries from dar_slave the data requested by dar. This way, only needed data get transmitted over pipes, which cannot be possible with a single pipe.

A3 - if you restore for example the file usr/bin/emacs dar will first restore usr (if the directory already exists, it will get its date and ownership restored, all existing files will be preserved), the /usr/bin is restored, then usr/bin/emacs is restored. Thus 3 inodes have been restored or modified while only one file has been asked for restoration.

A4 - For any binary package, ask your distro maintainer to include dar (if not already done), and check on the web site of your preferite distro for a dar package.

Q5 - If you give to dar an argument which is not an option, up to version 2.2.x it is interpreted as "to save that file only". Let's take an example:

   dar -c my-files -y -s 2045M data

reports

 --------------------------------------------
 31754 inode(s) saved
 with 0 hard link(s) recorded
 0 inode(s) not saved (no file change)
 0 inode(s) failed to save (filesystem error)
-> 147 files(s) ignored (excluded by filters)
 0 files(s) recorded as deleted from reference backup
 --------------------------------------------

the 147 files are due to the fact dar has excluded 147 files and directories which are not "data" in the current directory.

Note also that the use arguments out of options like "data" is deprecated since version 2.2.0, you would rather use -g option:

   dar -c my-files -y -s 2045M -g data

In version 2.3.x such arguments which are not options will have another meaning.

A6 - Yes, you can. No, there is no risk to have dar deleting the files that
were not selected for the differential backup. Here is the way dar works:

During a backup process, when a file is ignored due
to filter exclusion, an "ignored" entry is added to the catalogue
however. At the end of the backup, dar compares both catalogues the one
of reference and the new one built during the backup process, and adds a
"detruit" (destroyed in English) entry, when an entry of the reference
is not present in the new catalogue. Thus, if an "ignored" is present no
"detruit" will be added for that name. Then all "ignored" entries are
removed and the catalogue is dumped in the archive.
