About changing the AdvancedDisk disk pool size
Two methods exist to change the size of a disk pool, as follows:
If you use a logical volume manager, you can use it to change the size of a disk volume by adding LUNs to it. If you do, you must inventory the disk pool so that NetBackup reads the new size of the pool.
If you do not use a logical volume manager, you can change the size by adding or removing volumes from the disk pool.