Multiple address spaces for DFSMShsm allows you to start multiple DFSMShsm hosts in a single z/OS image.

An HSMplex can consist of both single and multiple DFSMShsm-host environments. There are several advantages to starting more than one DFSMShsm host in a z/OS image:

• Less work per address space and less contention between functions.
• Each address space that is doing some part of DFSMShsm's work can have an appropriate MVS™ dispatching priority for that type of work.
• A larger number of tasks are provided that perform any given DFSMShsm function; for example, migration.
• DFSMShsm functions that operate in more than one address space allow more MIPs that are allocated to DFSMShsm functions.