Placing objects in user disk pools, also called auxiliary storage pools (ASPs) in the character-based interface, can provide several advantages. These include the following:
By separating libraries, documents, or other objects in a user disk pool, you protect them from data loss when a disk unit in the system disk pool or other user disk pool fails. For example, if you have a disk unit failure, and data contained on the system disk pool is lost, objects contained in user disk pools are not affected and can be used to recover objects in the system disk pool. Conversely, if a failure causes data that is contained in a user disk pool to be lost, data in the system disk pool is not affected.
Using disk pools can also improve system performance. This is because the system dedicates the disk units that are associated with a disk pool to the objects in that disk pool. For example, suppose you are working in an extensive journaling environment. Placing journals and journaled objects in a Basic disk pools can reduce contention between the receivers and journaled objects if they are in different disk pools, which improves journaling performance. If you use independent disk pools to reduce contention, place the objects to be journaled in the primary disk pool and journal receivers in one or more secondary disk pools.
Placing many active journal receivers in the same disk pool is not productive. The resulting contention between writing to more than one receiver in the disk pool can slow system performance. For maximum performance, place each active journal receiver in a separate user disk pool.
You can use different disk protection techniques for different disk pools. You can also specify different target times for recovering access paths. You can assign critical or highly used objects to protected, high-performance disk units. You might assign large, low-usage files, like history files, to unprotected, low-performance disk units.