Migrating a multibos instance of AIX

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If you previously ran the multibos command to create a standby BOS, and restarted the system so that the standby BOS becomes the active BOS, and then removed the new standby BOS, you are running the AIX® operating system in an environment that does not have hd5, hd4, hd2, hd9var, and hd10opt logical volumes, but instead the bos_hd5, bos_hd4, bos_hd2, bos_hd9var, and bos_hd10opt logical volumes exist. Your system is still recognized as a root volume group (rootvg) during an operating system installation, and the logical volume names are changed to their original names during the migration (or preservation) installation. If you use network alternate disk migration (nimadm command) to perform the migration, the logical volume names are changed when you boot the altinst_rootvg volume group created by the nimadm process for the first time.

If you are running the operating system that has the bos_* logical volumes (that is, the bootinfo -v command returns bos_hd5), but also have a standby instance that has the original hd* logical volume names, the standby instance is treated as the rootvg during a migration or preservation installation, and the bos_* logical volumes remain unchanged. If you want to migrate the instance that has bos_* logical volumes, remove the standby BOS by using the multibos -RX command.

You must always back up your system before you migrate an operating system. Before you migrate, copy the usr/lpp/bos/pre_migration file from the media or from your network installation manager (NIM) Shared Product Object Tree (SPOT) of the level to which you are migrating, to a location on the target system. Run the file on the target system to check for any migration warnings.

Note: Before you perform a migration or a preservation type of operating system installation in this environment, verify that the disk control block has a valid level for your rootvg. You can run the /usr/lpp/bosinst/blvset -d /dev/hdiskN -g level command, where hdiskN is the disk that contains the bos_hd5 logical volume. If this command returns 0.0, run the bosboot -ad /dev/ipldevice command to correct it, and run the blvset command again to verify the rootvg level. The command must return 6.1 or 7.1.

If you have both standby and active BOS on the system, remove the standby BOS. The originally created hd* logical volumes are treated as the operating system, whether it is active or not.