MVS storage above region

MVS™ storage above region is the storage that is left between the top of the region and the bottom of the high private area. Usually 200 KB to 300 KB of free storage is maintained to allow for use by the termination routines if these is an abend.

If this free storage is not enough for recovery termination management (RTM) processing, the address space might be terminated with a S40D abend that does not produce a dump.

This area can be very dynamic. As the high private area grows, it extends down into this area, and the CICS® region can extend up into this area up to the value specified in IEALIMIT.