Multibos support

You can use multibos to deploy technology level or service pack updates to endpoints with a standby base operating system (BOS) instance without impacting the active BOS instance. By doing so, you can ensure continuous operation of the AIX operating system on the endpoint.

With multibos, you can create two separate bootable instances of the BOS within the same root volume group (rootvg). You can simultaneously maintain these two bootable instances of a BOS. The instance of a BOS that is associated with the booted boot logical volume (BLV) is the active BOS, while the other instance that has not been booted is called the standby BOS. Only two instances of BOS are supported per rootvg.

Use multibos in environments with tight maintenance windows to manage system downtime and risk when upgrading the endpoints.


The following are the general requirements and limitations on operating system, space, and logical volumes for multibos:
  • The multibos utility is supported on AIX version 5.3 with the 5300-03 Recommended Maintenance package and higher versions.
  • The current rootvg must have enough space for each BOS logic volume.
  • The total number of copied logical volumes cannot exceed 128. The total number of copied logical volumes and shared logical volumes are subject to volume group limits.
The AIX Advanced Deployment Wizard was enhanced to include a section mainly for the following multibos operations:
  • Multibos express task: Creating a BOS and deploying TL or SP updates to it
  • Creating a standby BOS
  • Deploying TL or SP updates
  • Updating the boot list
  • Removing a standby BOS
For more information, see Multibos utility overview.