IMSID= parameter for procedures

Use the IMSID= parameter in a procedure to specify a 1- to 4-character IMS identifier for the IMS control region, IMS dependent regions, or IMS batch region.

For the IMS control region

The IMSID= parameter specifies a 1- to 4-character identifier that is a valid subsystem identifier for the operating system being used. It overrides the identifier specified at the time of system definition of the running IMS system.

For IMS dependent regions

The IMSID= parameter specifies a 1- to 4-character identifier that is a valid subsystem identifier for the operating system to which this dependent region connects. It overrides the identifier specified at the time of system definition of the running IMS system.

You can set the IMSID= parameter for dependent regions using the DFSOPT DD statement in IMS-supplied procedures. The syntax for the IMSID= parameter is:

IMSID=char str (No default)

For more information, see DFSOPT DD in DD statements for IMS procedures.

For the IMS batch region

The IMSID= parameter specifies a 1- to 4-character IMS identifier that is used in IMS messages that are written to the system log. It overrides the identifier specified at the time of system definition of the running IMS system.

Recommendation: Specify a unique IMSID for each batch region. This helps to avoid confusion as to which region has issued a console message.

Additional guidelines

Do not use characters for the IMSID that match the beginning characters of a z/OS® command. If the IMSID is the same as the beginning characters of a z/OS command, that command does not work after you start IMS. For example, if you start IMS with IMSID=D, z/OS does not respond to any of the z/OS display commands such as D A,L.

For online control regions, the IMSID must be different from any other IMS subsystem identifier or non-IMS subsystem identifier defined to the operating system under which IMS is running. This identifier is also used to relate messages that are routed to the z/OS system console with the corresponding IMS system. To avoid confusion as to which region has issued a console message, specify a unique IMSID for each batch region. This is however, not a requirement.

The IMSID name must not be the same as the procedure name that starts IMS unless one of the following is true:
  • All DD statements in the startup procedure are cataloged in the master catalog.
  • The unit and volume are specified on each DD statement.

This parameter cannot be changed at emergency restart.

An IMSID name specified in the FDR procedure identifies the subsystem name for the FDR region.