Before you stop a CAS, you should ensure that the MAXUSER, RSVNONR, and RSVSTRT parameters in IEASYSxx contain values that, in combination, will not allow the system to run out of usable ASIDs. To conserve overhead, you may want to limit the value specified for MAXUSER and use values for RSVNONR and RSVSTRT that allow for replacement of nonreusable address spaces when the value at MAXUSER has been exceeded.
The total number specified for MAXUSER and RSVNONR should be greater than zero. The sum of the values specified for MAXUSER, RSVNONR, and RSVSTRT cannot be greater than 32767, which is also the maximum for MAXUSER. For more information about the MAXUSER, RSVNONR, and RSVSTRT parameters, see the MVS/ESA Initialization and Tuning Reference manual.
Once a CAS is running, you should not need to stop it unless you want to change its operating parameters.
If you want to stop a CAS, whether it is running as a started task or as a batch job, do the following:
The CMASs can continue to run without a CAS, but you cannot access them through either the ISPF end-user interface or the application programming interface (API). You may want to leave the CMASs running if either of the following is true:
Any CMAS that is running when you restart the CAS automatically reconnects to the CAS.
P casname
where casname identifies the CAS you want to stop.
BBMZA999I CAS(ssid) Shutdown Complete - CC=nn
where ssid identifies the CAS that was stopped and nn is the completion code.