What is meant by the MVS link pack area?

The MVS™ link pack area comprises several areas, both above and below 16 MB. In these topics, the term MVS link pack area refers to the pageable link pack areas above and below 16 MB where modules that are used from the MVS link pack area are normally installed.

The MVS link pack area has both pageable and fixed parts. Although you can install CICS® modules into the fixed parts, use the pageable areas for performance reasons.

The term LPA specifically refers to the MVS link pack area below 16 MB, and the term ELPA specifically refers to the area above 16 MB. A module that is link-edited with the RMODE(ANY) attribute is loaded into the ELPA.

If you install a module into the LPA or ELPA, that module cannot be retrieved from the MVS link pack area until you re-IPL your MVS with CLPA specified. To use the new module and avoid an IPL, you can use the MVS dynamic LPA in one of the following ways:
  • With the SETPROG LPA command
  • With an LPA statement in a PROGxx member of PARMLIB, which specifies the SET PROG=xx command