Setting address space storage limits for a CICS region
When you submit your CICS job, set the z/OS parameters REGION and MEMLIMIT to specify the amount of virtual storage for the address space in which CICS runs.
About this task
You cannot alter the REGION and MEMLIMIT values for the CICS® region while CICS is running. You can specify new values only when you start the CICS region.
The REGION parameter specifies your request for an amount of 24-bit and 31-bit storage, that is, storage below the bar, for the CICS address space. Up to 2047 MB of storage can be requested, but you must leave enough storage below the bar for the system region in 24-bit storage, and items in the high private area such as the local system queue area (LSQA). You can specify the REGION parameter in different ways to request a specific amount of storage, or all the available 24-bit or 31-bit private storage. The resulting region size below the bar can be unpredictable.
The MEMLIMIT parameter specifies the limit of 64-bit (above-the-bar) storage for the CICS region. A CICS region needs a MEMLIMIT value of at least 6 GB. The default value in z/OS® for MEMLIMIT is 2 GB.