PLEXCFG

PLEXCFG={XCFLOCAL   }
        {MONOPLEX   }
        {MULTISYSTEM}
        {ANY        }

Specifies the type of configuration into which the system is allowed to IPL. You can specify one or more of the following system configurations:

PLEXCFG=MULTISYSTEM

Specifies that the system is to be part of a sysplex consisting of one or more MVS™ systems that reside on one or more processors. The same sysplex couple data sets must be used by all systems.

You must specify a COUPLExx parmlib member that identifies the same sysplex couple data sets for all systems in the sysplex (on the COUPLE statement) and signalling paths between systems (on the PATHIN and PATHOUT statements). You must also specify in the CLOCKxx parmlib member whether you are using a Sysplex Timer that is real (ETRMODE=YES) or simulated (SIMETRID=YES).

Use MULTISYSTEM when you plan to IPL two or more MVS systems into a multi-system sysplex and exploit full XCF coupling services. GRS=NONE is not valid with PLEXCFG=MULTISYSTEM.

PLEXCFG=XCFLOCAL

Specifies that the system is to be a single, standalone MVS system that is not a member of a sysplex and cannot use couple data sets. The COUPLExx parmlib member cannot specify a sysplex couple data set, and, therefore, other couple data sets cannot be used. Thus, functions such as WLM, that require a couple data set, are not available.

In XCF-local mode, XCF does not provide signalling services between MVS systems. However, multi-system applications can create groups and members, and messages can flow between group members on this system. If signalling paths are specified, they are tested for their operational ability, but they are not used.

Use XCF-local mode for a system that is independent of other systems. In XCF-local mode, XCF services (except permanent status recording) are available on the system and you can do maintenance, such as formatting a couple data set or changing the COUPLExx parmlib member. The IBM-supplied default parmlib member COUPLE00 and the COUPLE=** system parameter are intended to be used to bring up the system in XCF-local mode.

PLEXCFG=MONOPLEX

Specifies that the system is to be a single-system sysplex that must use a sysplex couple data set. Additional couple data sets, such as those that contain policy information, can also be used. XCF coupling services are available on the system, and multi-system applications can create groups and members. Messages can flow between members on this system (but not between this system and other MVS systems) through XCF signalling services. If signalling paths are specified, they are not used.

You must specify a COUPLExx parmlib member that gives the system access to a sysplex couple data set to be used only by this system. When a system IPLs into a single-system sysplex, no other system is allowed to join the sysplex.

Use MONOPLEX when you want only one system in the sysplex (for example, to test multi-system applications on one system) or when you want to use a function, such as WLM, that requires a couple data set.

PLEXCFG=ANY

Specifies that the system can be part of any valid system configuration. Specifying ANY is logically equivalent to specifying XCFLOCAL, MONOPLEX, or MULTISYSTEM. ANY is the default.

Generally avoid specifying PLEXCFG=ANY and explicitly specify the sysplex environment that you intend for the system to join. See z/OS MVS Setting Up a Sysplex for additional information about the PLEXCFG parameter and planning for XCF-local mode.

To prevent the operator from overriding the PLEXCFG parameter, specify OPI=NO on the PLEXCFG keyword in the IEASYSxx parmlib member. (For example, PLEXCFG=MULTISYSTEM,OPI=NO).

Default Value: PLEXCFG=ANY

Associated Parmlib Member: None