The MVS common area

The MVS™ common area contains a number of nucleus, queue, link pack, common service, and storage areas.

The following areas comprise the MVS common area:
  • Nucleus and extended nucleus
  • System queue area (SQA and ESQA)
  • Link pack areas (PLPA, MLPA, and CLPA)
  • Common service areas (CSA and ECSA)
  • Prefixed storage area (PSA).

All these elements of the common area, except the PSA, are duplicated above 16 MB.

Figure 1. Virtual storage map
A common area below the 1 MB boundary is 4 KB and contains the PSA. A private area above the common area and up to the 1 MB boundary contains JES, IMS DC, IMS MPP, CICS, TSO, z/OS Communications Server and BATCH areas. A common area above the 1 MB boundary and up to the 16 MB line contains the CSA, PLPA, FLPA, MLPA, SQA, nucleus and V=R. An extended common area above the 16 MB line contains the extended nucleus, the extended SQA, the extended MLPA, FLPA and PLPA, and the extended CSA. An extended private area above the extended common area and up to 2 GB contains JES, IMS DC, IMS MPP, CICS, TSO, z/OS Communications Server, BATCH and DB2 areas.