NSR_CRASH(8)

NAME
nsr_crash - How to recover from a disaster with NetWorker

DESCRIPTION
NetWorker can be used to recover from all types of system and hardware failures that result in loss of files.

When a NetWorker client has lost files, the recover command can be used to browse, select, and recover individual files, selected directories, or whole filesystems. If the networker recover command is lost or damaged, it will have to be copied either from a NetWorker client or from the NetWorker distribution media.

When recovering a large number of files onto a filesystem that was only partially damaged, you may not want to overwrite existing versions of files. To do this, wait until recover asks for user input to decide how to handle recovering an existing file. You can then answer N meaning ``always no'' to cause recover to avoid overwriting any existing files, or n if you want to protect this file but you want recover to ask again on other files.

If you do want to replace the existing version of a file or set of files with the saved versions, answer Y or y when recover asks if it should overwrite existing files (Y means ``always yes'' for future overwrite cases; y means just overwrite this one file).

For more information on using the recover command, see the recover(8) manual page.

If the NetWorker server daemons or commands are lost, it may be necessary to re-install the server from the NetWorker distribution media. Once the NetWorker server is installed and the daemons are running, other NetWorker server files can be recovered using the recover command. When re-installing NetWorker you must be sure to install the /nsr directory in exactly the same place as it was originally installed. The machine used to recover files may be different that the one used to save the files, but it must have the same hostname as the original machine. Recovery of the NetWorker server and client indexes requires that the destination machine be of the same kind as the one used to save the indexes.

If the NetWorker server's media database is lost, it will be necessary to recover the bootstrap from media. mmrecov recovers the bootstrap which contains the media database and the NetWorker server resource files. Since the resource files cannot be restored on top of the ones the NetWorker server is using, it is necessary to shut down NetWorker, rename the recovered resource files, and restart NetWorker. The save set identifier and other information about the bootstrap save set is printed by savegrp at the end of each scheduled save. It can also be displayed using mminfo -B or scanner -B.

See the savegrp(8), mminfo(8), and scanner(8) man pages for more details.

If the index of any NetWorker server or client is lost, the index must be recovered from backup media before the recover command can be used to browse and recover files that were saved from that client. To recover the NetWorker server or any other client's index once the media database and server resource files have been recovered, use the nsrck command. The nsrck command recovers the lost index for a NetWorker server or client by locating the index:clientname save set produced by the savegrp(8) command at the end of a scheduled save. nsrck queries the media database to determine which save sets to extract from which volumes to recover the index to the latest time. See the nsrck (8) man page for more details.

To summarize, these are the steps you must do to recover your server after mmrecov completes.

1.  Shut down your NetWorker server (nsr_shutdown -a).

2.  Change to the /nsr directory (cd /nsr).

3.  Save the temporary resource directory created when you reinstalled the NetWorker server (mv res res.save).

4.  Move the recovered resource directory into place (mv res.R res).

5.  Restart the NetWorker server (cd / ; nsrd).

6.  After verifying that the recovered resources are valid, remove the temporary resource directory (rm -r /nsr/res.save).

7.  Recover your server and client indexes (nsrck -L7).

NOTE:
    The mmrecov command is only used to recover the NetWorker server's media database and resource files. Use nsrck to recover the server and client indexes.

Once the media database and server resource files have been recovered, you may recover any of your server or client indexes in any order. It is not necessary to recover the server's index before recovering the clients' indexes. Moreover, if your clients have the NetWorker client installed, you may run on-demand and scheduled saves once the media database and server resource files have been recovered. However, you will not be able to browse the saves for a client until you recover the client's file index. You may use save set recover to recover files before a client's file index has been recovered.

See the recover(8) man page for details on running recover by save set.

If the server is damaged so badly that it will not run at all, you will need to follow the manufacturer's instructions for re-installing and rebooting a multiuser system. Once you have the system up and running in multiuser mode, you can re-install NetWorker (that is extract NetWorker from the distribution media and install it, using nsr_ize(8), pkgadd(1M), or any other installation utility depending on your system), use mmrecov to recover the media database and resource files, and use nsrck to rebuild the on-line indexes for the server and each client. Finally, you will want to recover files which previously existed on the machine, but which do not exist on the manufacturer's distribution media. This may include system files which had been customized, a specially tailored kernel, new special device entries, locally developed software, and users' personal files.

SEE ALSO
nsr_ize(8), nsr_layout(5), nsr(8), nsrck(8), recover(8), savegrp(8), mmrecov(8), scanner(8)