GRS

GRS={JOIN   }
    {TRYJOIN}
    {START  }
    {NONE   }
    {STAR   }

This parameter specifies whether the system being initialized is to participate in a global resource serialization complex. In a multisystem sysplex, every system in the sysplex must be in the same global resource serialization complex. This allows global serialization of resources in the sysplex.

Specifying GRS=STAR indicates that the system being initialized is to participate in a global resource serialization star complex.

GRS=NONE indicates that the system is not to participate in a global resource serialization complex. GRS=START, GRS=JOIN, and GRS=TRYJOIN indicate that the system is to coordinate global resource requests with other systems in a global resource serialization ring complex.

Specifying GRS=START indicates that the system is to start a global resource serialization ring complex and honor the requests of other systems (those systems that specify GRS=JOIN) to join the complex. Specifying GRS=JOIN indicates that the system is to join an existing ring complex of active global resource serialization systems and also honor the requests of other systems to join the complex.

Specifying GRS=TRYJOIN allows the system to act on whether a ring complex already exists. If the complex does exist, the system joins the existing complex. If the system does not find any active global resource serialization systems, the system will start the complex.

Attention: When all the systems in a global resource serialization ring complex are not in a multisystem sysplex, there is a possibility of a split ring and a data integrity exposure when GRS=TRYJOIN is used. When all systems are in a multisystem sysplex, however, this option is recommended. For more information about specifying the GRS system parameters, see z/OS MVS Planning: Global Resource Serialization.

Note: If you have specified anything other than GRS=NONE, then you must specify the GRSRNL parameter.

Value Range: Not applicable

Default Value: None

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