Alternate bootsets for workload partitions

In a logical partition (LPAR) there are two commonly used techniques for creating a backup of the LPAR. The mksysb command can be used to create a backup image of the rootvg in a file or on a device, or the alt_disk_copy command can be used to make a copy of the rootvg disks on an alternate set of disks.

The alt_disk_copy command is used during a maintenance cycle. It allows the current root volume group to be saved on alternate disks before updates are applied. If any issues occur with the updated system, the LPAR can be restarted from the alternate disks to switch back to the previous system level.

In a WPAR, the savewpar command provides function similar to the mksysb command for an LPAR. You can create an alternate bootset for a WPAR that corresponds to use of the alt_disk_copy command in an LPAR.

The chwpar command with the -B option allows cloning of the current bootset of a WPAR to create an alternate bootset. For a file system-based WPAR, a volume group might be specified to create the alternate bootset on. If volume group is not specified, the alternate bootset is created on the same volume group where the current bootset is stored.

The chwpar command with the -b option might be used to specify a bootlist, which gives an ordered list of bootsets on which a WPAR should be started from. If the start from the first bootset in the bootlist fails, then startwpar command will retry to use the next bootset in the list.

The lswpar command also displays information about bootsets and bootlists.