Parmlib members contain parameter values that MVS™ uses as input during system initialization to define the characteristics of the system.

For an MVS system to run in a sysplex, you must specify certain values in the IEASYSxx and the COUPLExx parmlib members. Certain systems running in a PR/SM™ partition can specify values for the XCFPOLxx parmlib member.

And, depending on the way you set up your sysplex, you can also specify values for the IEASYMxx and the LOADxx parmlib members.

This section provide background information and considerations for selecting values for these parmlib members. You might find it helpful to supplement the planning information here with the corresponding reference information from z/OS MVS Initialization and Tuning Reference.