Archive for March, 2009

Restoring Files From Aix mksysb Backup

Tuesday, March 31st, 2009

You may be aware that the mksysb command creates the bootable image of all the mounted files systems on rootvg, at the time of creation of mksysb image. Here I am going to discuss how to restore data from mksysb backup image. I’ll discuss how to restore single file, multiple files and directories from mksysb backup image.

Those interested in knowing more about mksysb backup image contents can read my earlier article What is mksysb And What Are Its Components. For those who want to read all of my aix backup articles can follow backup link in categories list shown on this page. Just to be brief, backup resides in the fourth file image on the tape. First three are BOS boot image, mkinsttape image and dummy TOC.

Restoring Data From The mksysb Image

Restoring A Single File From mksysb Image

Let’s say you want to restore a file /etc/rc from mksysb image from tape /dev/rmt1. Now you have to follow the following procedure:

  1. Rewind the tape back to starting position.
  2. Skip the first 3 parts of mksysb image.
  3. Extract the file from the 4th part of the mksysb image.

Rewind The tape: tctl -f /dev/rmt1 rewind

Restore the file: restore -x -d -q -s4 -f /dev/rmt1.1 ./etc/rc

-s4 Signifies that we seek 4th image on the tape, where the backup resides.

Use rmt1.1, means no rewind on close and no retension on open.

Note the ./etc/rc, the “.” is a must, because all paths are absolute and not relative.

If the backup was taken with -i flag, you can use the following command:

restore -x -d -v -q -f /dev/rmt1 /etc/rc

You have to use -d flag.

If the mksysb backup was taken with file system backup, you can use the following command:

restore -x -v -q -f /dev/rmt1 /etc/rc

Restoring A Directory File From mksysb Image

Let’s say you want to restore a full directory /var/adm from the mksysb archive on /dev/rmt1. Here you have to specify the directory name instead of a single file:

Rewind The tape: tctl -f /dev/rmt1 rewind

Restore the file: restore -x -d -s4 -f /dev/rmt1.1 ./var/adm

Similarly if the backup was taken with -i option then it will be:

restore -x -d -v -q -f /dev/rmt1 /var/adm

If the backup was taken with filesystem backup option then it will be:

restore -x -v -q -f /dev/rmt1 /var/adm

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