Expanded Storage Management with MVS/ESA

Expanded storage is offered as a relatively inexpensive way of using high speed processor storage to minimize I/O operations. Under many circumstances, expanded storage achieves this objective. In some situations, the expanded storage algorithms may not yield the expected benefits. In a few situations, expanded storage can cause severe performance problems. This paper describes the concepts and algorithms used to manage expanded storage with MVS/ESA and highlights major changes between MVS/XA and different releases of MVS/ESA.