Disabling MSC with the MSC= execution parameter

You can disable the Multiple Systems Coupling (MSC) feature in an IMS system by specifying MSC=N in the IMS execution parameters and cold starting IMS.

When MSC=N is specified, no MSC resources or control blocks are loaded during IMS initialization. Any MSC parameters that are specified in the DFSDFxxx or DFSDCxxx PROCLIB members are ignored. Any MSC definitions in the stage-1 system definition input are also ignored.

Alternatively, you can also disable MSC by removing all MSC definitions from the IMS system definition stage-1 input and omitting the MSC= execution parameter. When no MSC stage-1 system definition input is present, MSC=N is the default.

To disable MSC:

Procedure

  1. Specify MSC=N in the IMS execution parameters.
    The MSC= parameter can be specified in the IMS or DCC startup procedure in the DFSPBxxx member of the IMS PROCLIB data set.
  2. Cold start IMS.
  3. Confirm that MSC is disabled by checking the MSC= specification in the final DFS1929I message that is issued at the end of startup.