The SETSYS SWAP|NOSWAP command determines whether the DFSMShsm address space can be swapped out of real storage.

Guideline: The NOSWAP option is recommended. DFSMShsm always sets the option to NOSWAP when the ABARS secondary address space is active.

In a multisystem environment, DFSMShsm also always sets the option to NOSWAP so that cross-system coupling facility (XCF) functions are available. See DFSMShsm in a sysplex environment for the definition of a multisystem (or a sysplex) environment.