Normally, soft and hard limits are not changed when a new process is created unless the creating process requests a change. Both the soft limits and the hard limits are set to the value that was specified the parent's inheritance structure, if it is requested. The values of both limits are raised to the hard limit if a child was spawned with a new identity, or if an exec occurred after the identity was changed.

Setting a global value in BPXPRMxx (using the MAXASSIZE parameter) provides the values that the system will use to assign to all processes. The RACF® security administrator can override these values by defining the MEMLIMIT value for individual identities in the associated OMVS segment.

The only time MEMLIMIT or ASSIZE from the OMVS segment is used to define these limits for inheritance is with a spawn with identity change or an exec after setuid. For more details, see What happens when an identity change occurs?.