Planning the couple data sets

A sysplex requires a sysplex couple data set to store information about its systems, the XCF groups and members running in the sysplex, and general status information. And, depending on the policies you define to help manage resources and workload for the sysplex, you might need to define additional couple data sets to store policy or function-related information.

The coupling facility resource management (CFRM) couple data set holds the CFRM policy, which allows you to define how MVS™ is to manage your coupling facility resources.
The sysplex failure management (SFM) couple data set holds the SFM policy, which allows you to define how system failures, signaling connectivity failures, and PR/SM™ reconfiguration actions are to be managed.
The workload management (WLM) couple data set holds the WLM policy, which allows you to define service goals for workloads.
The automatic restart management (ARM) couple data set holds the policy that defines how MVS is to manage restarts for specific batch jobs and started tasks that are registered as elements of automatic restart management.
The system logger (LOGR) couple data set holds the policy that allows you to define log stream or structure definitions.
The OMVS (BPXMCDS) couple data set contains system usage and mount information.

Each of these types of functional data, along with real-time information about the sysplex and the resources being managed when the function is in use, resides in a couple data set. Policy specifications and function-specific data cannot reside in the sysplex couple data set, but you can combine data for different functions in the same couple data set.

Before you can define and activate a policy or use this function-specific data, you must format a couple data set to hold the policy, data, or both; you must also ensure that the data set is available to the systems in the sysplex that need it. This topic describes what you need to consider when planning couple data sets for a sysplex.

Many of the things you need to consider when planning couple data sets are common to all couple data sets. However, requirements for connectivity, formatting, and definition differ between the sysplex couple data set and the couple data sets that hold function-specific information. Information about these topics is presented, as follows: