Adding optional storage-class memory (SCM) on Flash Express® cards to your auxiliary storage can increase paging performance and flexibility. Even with SCM usage, page data sets on DASD are required for auxiliary storage. With the exception of VIO data, which must remain on page data sets, all other data types can be paged out to SCM. ASM pages out from main memory to either storage medium based on the response times and on data set characteristics, critical paging requirements, disk availability (during a HyperSwap® failover, for example) and available storage space. For additional information, refer to Auxiliary storage management initialization.

Figure 1 depicts the required auxiliary storage management page data sets with the addition of optional SCM. For additional information on using SCM, refer to Auxiliary storage management initialization and the PAGE, PAGESCM, NONVIO and PAGTOTL parameters of parmlib member IEASYSxx in z/OS MVS Initialization and Tuning Reference.

Figure 1. Auxiliary storage diagram with SCM