Multisystem sysplex configuration on PR/SM

This topic describes a multisystem sysplex on PR/SM™. Note that an XCF-local mode or single-system sysplex can be established on PR/SM similar to those shown in XCF-local mode configuration and Single-system sysplex configuration.

Purpose: Use multisystem sysplex mode on PR/SM for the reasons listed in Multisystem sysplex configuration without an existing global resource serialization complex and Multisystem sysplex configuration with an global resource serialization complex. A multisystem sysplex on one processor with PR/SM can use a Sysplex Timer or a simulated Sysplex Timer.
Required System Parameters: Use the following system parameters to IPL each MVS™ system on one processor on PR/SM:
- CLOCK=xx specifies the CLOCKxx parmlib member that requests either:
  - The same simulated Sysplex Timer (SIMETRID xx) on all systems, or
  - The same Sysplex Timer (ETRMODE YES) to be used on all systems.
    If the sysplex spans more than one processor, ETRMODE YES is required for all systems.
- Other system parameters for a multisystem sysplex as described in the preceding topics.

As each of the MVS systems is IPLed, the sysplex consists of one, two, three, and then four systems. XCF coupling services and global resource serialization are available on the systems as they complete initialization.

See On PR/SM - Physical configuration of a sysplex on LPARs and Controlling availability and recovery through XCFPOLxx (PR/SM only) for additional information about PR/SM configurations.