System Backup and Restore

System Backup

It is strongly recommended to regularly perform system backups, especially each time the system is modified.

Backups can be performed either on tape, on DVD-RAM or using NIM (recommended procedure).

It is very important to note the oslevel -s

result of the backup performed which will be very useful to perform the mksysb restore.

At last, check your backup running :

• smit lsmksysb if your backup is on a media
• nim -o showres <mksysb_resource> if your backup is on a NIM server

System Restore

In most of the cases you will not be able to boot from a CD to restore a backup done on a tape or a DVD. That comes from a compatibility problem between the AIX Technology Level of the mksysb and the AIX Technology Level of the bootable CD.

To be able to boot from an AIX CD to restore a mksysb tape, the Maintenance Level of the 2 products must be identical. For example, if the AIX Technology Level of the mksysb is 5300-10-03-1013, the AIX Technology Level of the system used to boot must be at the 5300-10-03-1013 ( 5300-10-00-0000 does not work).

Due to the fact that most of the system Technology Levels are built from an AIX base CD + an update CD + a downloaded Service Pack, it will not be possible to find such a bootable CD.

So, the only solution is to boot from the tape, the DVD-RAM or a spot created from the mksysb (using NIM).

Booting on an AIX system level lower than the system level will lead to errors and impossibility to restore your backup.

Performing an access to rootvg disk using the Maintenance Menu, you get the same problem : the AIX Maintenance Level of the  rootvg and the AIX Maintenance Level of the media used to boot must match. In that case, you must perform the boot from a mksysb tape / DVD or SPOT.

Booting an AIX CD at a higher level than the mksysb one to restore it, will result in updating some filesets of the system, so the restored system AIX level will be changed.

System CLONE

Default installation of AIX 5.3 and AIX 6.1 systems allow mksysb systems to be restored on any other platform supporting the mksysb Technology Level. Contact your BULL representative to know if the mksysb Technology Level is compatible with the platform on which you need to install it.

To check if the system was installed with default options, have a look at the ALL_DEVICES_KERNELS variable in the /bosinst.data file. You must get :

ALL_DEVICES_KERNELS = yes

If you get "no", insert the AIX base CDs, run the smit install_bundle command then select the "AllDevicesKernels" bundle to be installed and perform a mksysb again.