A disk pool group is made up of a primary disk pool and zero or more secondary disk pools. Each disk pool is independent in regard to data storage, but in the disk pool group they combine to act as one entity. If you make one disk pool available or unavailable, the rest of the disk pools in the group are also made available or unavailable at the same time. Also, in a clustered environment, all of the disk pools in a group switch to another node at the same time.
An example of a practical use for a disk pool group is to isolate journal receivers from the objects for which they contain journal entries. The primary disk pool might contain the libraries, journals, and objects to be journaled, while the secondary disk pools might contain the associated journal receivers. The journals and journal receivers remain separate for maximum performance and recoverability, but they function together in the disk pool group.
If you delete a disk pool in a disk pool group, be aware of the effects it could have on other disk pools in the group. For example, when the original primary disk pool for a secondary disk pool is deleted, the existing secondary disk pool can be linked to a new primary disk pool only if that primary disk pool has never been made available.
Disk pool groups can only be implemented on OS/400® V5R2 or i5/OS™ V5R3 and later.