Disabling global online change

When disabling global online change you do not have to shut down all the IMS systems in the IMSplex at the same time. Also, after you disable global online change, the IMSplex only supports local online change.

When you are ready to disable global online change, perform the following steps on one IMS at a time:

Procedure

  1. Shut down IMS.
  2. Modify the DFSCGxxx PROCLIB member data set parameters for online change to enable local online change by changing OLC=GLOBAL to OLC=LOCAL.
  3. Run INITMOD job to initialize the MODSTAT data set.
  4. Include MODSTAT DD statements to IMS control region JCL.
  5. Include MODSTAT2 DD statements to IMS control region JCL (if XRF).
  6. Cold start the IMS.

Typically, an IMS that was down during global online change has to cold start when it comes back up. Cold start might be required to prevent restart from processing log records against the current online change libraries that do not match, potentially causing restart to fail or causing a severe error later on. However, if the IMS was down for only the last global online change and the restart does not conflict with the last global online change, then the IMS is permitted to warm start.

If an IMS was down during only the last online change and its restart type conflicts with the last online change type, or IMS was down for two or more global online changes, IMS must cold start.