Online Interface Administration › Defining Multiple VTAM Cross-Memory Regions › Regions Grouped by Operating System Subsystem Name

Regions Grouped by Operating System Subsystem Name

Multiple VTAM regions are grouped under a four-character operating system subsystem name. The SUBSYS= cross-memory parameter specifies the subsystem name at the startup time of the cross-memory region. Unless you specifically want to define separate multiple groups of VTAM regions, use the default SUBSYS parameter.

If you specify SUBSYS=, all VTAM regions grouped under the same SUBSYS must be started with the same release and PTF level of the CA View load libraries.

Important! If you change your release of CA View and you specified a value in SUBSYS=, you must change the SUBSYS= cross-memory parameter and IPL to prevent CSA damage. The control block sizes for CA View are release dependent and can cause serious problems if you do not specify the correct release. If you use the default parameter for SUBSYS, this problem does not occur because each release of CA View defaults to the appropriate SUBSYS name.