WAIT and NOWAIT MWE considerations

DFSMShsm keeps up to four NOWAIT MWEs on the CSA queue for each address space. Subsequent MWEs from the same address space are deleted from CSA when the MWE is copied to the DFSMShsm address space. When the number of MWEs per address space falls under four, MWEs are again kept in CSA until the maximum of four is reached. Table 1 shows the types of requests and how the different limits affect these requests.

Table 1. How Common Service Area Storage Limits Affect WAIT and NOWAIT Requests
Type of Request	DFSMShsm Active	DFSMShsm Inactive
Batch WAIT	If the current CSA storage is less than the maximum limit, the MWE is added to the queue. Otherwise, a message is issued and the request fails.	If the current CSA storage is less than the maximum limit, the operator is required to either start DFSMShsm or cancel the request.
TSO WAIT	If the current CSA storage is less than the active limit, the MWE is added to the queue. Otherwise, a message is issued and the request fails.	The operator is prompted to start DFSMShsm but the request fails.
NOWAIT	If the current CSA storage is less than the active limit, the MWE is added to the queue. Otherwise, a message is issued and the request fails.	If the current CSA storage is less than the inactive limit, the MWE is added to the queue. Otherwise, a message is issued and the request fails.

A system programmer can use the SETSYS command to change any one of these values. The SETSYS command is described in z/OS DFSMShsm Storage Administration.