A disk pool, also referred to as an auxiliary storage pool (ASP) in the character-based interface, is a software definition of a group of disk units on your system. This means that a disk pool does not necessarily correspond to the physical arrangement of disks. Conceptually, each disk pool on your system is a separate pool of disk units for single-level storage. The system spreads data across the disk units within a disk pool. If a disk failure occurs, you need to recover only the data in the disk pool that contained the failed unit.
Your system may have many disk units attached to it for disk pool storage. To your system, they look like a single unit of storage. The system spreads data across all disk units. You can use disk pools to separate your disk units into logical subsets. When you assign the disk units on your system to more than one disk pool, each disk pool can have different strategies for availability, backup and recovery, and performance.
Disk pools provide a recovery advantage if the system experiences a disk unit failure resulting in data loss. If this occurs, recovery is only required for the objects in the disk pool that contained the failed disk unit. System objects and user objects in other disk pools are protected from the disk failure.