Auxiliary storage

When more than a fixed percentage (constant MCCASMT1) of auxiliary storage slots have been allocated, SRM reduces demand for this resource by taking the following steps:

LOGON, MOUNT and START commands are inhibited until the shortage is alleviated.
Initiators are prevented from executing new jobs.
The target MPL (both in and out targets) in each domain is set to its minimum value.
The operator is informed of the shortage.
Choosing from a subset of swappable address spaces, SRM stops the address space(s) acquiring slots at the fastest rate and prepares the address space for swap-out (logical swap). When SRM swaps-out an address space because of excessive slot usage, SRM informs the operator of the name of the job that is swapped out, permitting the operator to cancel the job.

If the percentage of auxiliary slots allocated continues to increase (constant MCCASMT2), SRM informs the operator that a critical shortage exists. SRM then prevents all unilateral swap-ins (except for domain zero). This action allows the operator to cancel jobs or add auxiliary paging space to alleviate the problem.

When the shortage has been alleviated, the operator is informed and SRM halts its efforts to reduce the demand for auxiliary storage.