Using the multibos utility
The multibos utility allows you, as root, to create multiple instances of AIX® on the same root volume group (rootvg).
The multibos setup operation creates a standby base operating system (BOS) that boots from a distinct Boot Logical Volume (BLV). This creates two bootable instances of BOSes on a given rootvg. You can boot from either instance of a BOS by specifying the respective BLV as an argument to the bootlist command, or using system firmware boot operations.
You can simultaneously maintain two bootable instances of a BOS. The instance of a BOS associated with the booted BLV is the active BOS. The instance of a BOS associated with the BLV that has not been booted is the standby BOS. Only two instances of BOS are supported per rootvg.
The multibos utility allows you to access, install, maintain, update, and customize the standby BOS either during setup or during any subsequent customization operations. Installing maintenance or technology level updates to the standby BOS does not change system files on the active BOS. This allows for concurrent update of the standby BOS, while the active BOS remains in production.
The multibos utility has the ability to copy or share logical volumes and file systems. By default, the multibos utility copies the BOS file systems (currently the /, /usr, /var, /opt, and /home directories), associated log devices, and the boot logical volume. You can make copies of additional BOS objects (see the –L flag). All other file systems and logical volumes are shared between instances of the BOS. Separate log device logical volumes (those not contained within the file system) are not supported for copy and will be shared.