In a single-system environment, a dedicated (or stand-alone), independent disk pool can be varied off independent of other disk pools because the data in the independent disk pool is self-contained. That is, all of the necessary system information associated with the independent disk pool's data is contained within the independent disk pool. The independent disk pool can also be varied on while the system is active; that is, no initial program load (IPL) is required. Using independent disk pools this way can be useful, for example, if you have large amounts of data that are not needed for day-to-day business processing. The independent disk pool containing this data can be left varied off until it is needed. When large amounts of storage are routinely kept varied off, you can shorten processing time for operations such as IPL and reclaim storage.
In the figure, the user has five independent disk pools. They can represent three different applications where the third application might have archived data. The system automatically creates the system disk pool (referred to as Disk Pool 1 or ASP 1), which contains all system programs and system data.
