Configuring mksysb image on system backup tapes
Use the mksysb command
to ensure that the boot image, BOS Installation/Maintenance image, and the
table of contents image are created with a tape block_size value of
512.
Bootable mksysb tapes
comprise the following images:
·
Boot image
·
BOS
Installation/Maintenance image
·
Table of contents image
·
System backup image
The system backup image is the actual backup of the files in the
rootvg in all JFS-mounted file systems.
The boot
image, BOS Installation/Maintenance image, and the table of contents image must
be created with a tape block_size value of 512. The mksysb command ensures that the
block size is 512 when these images are created. There are no restrictions on
the block size used for the fourth (system backup image) on the tape. The block
size of the system, before it was temporarily set to 512, is used for the
fourth image on the tape.
The value
of the block size must be saved in the /tapeblksz file in the second image
on the tape. The second and fourth images are stored in backup/restore format.
Again, mksysb ensures the correctness of the tapes created by using the mksysb command.
If there
are problems with the bosinst.data file, the image.data file, or the tapeblksz file, these files can be restored from the second image on the
tape and checked. These files, as well as commands necessary for execution in
the RAM file system (when running in maintenance mode after booting from the
tape), are stored in the second image.
Restoring a file from the second image or tape
