Prerequisite considerations

Find information about the prerequisite considerations that you must review before you start implementation of the maintenance procedures.

Before you start the maintenance procedures, evaluate if the following conditions apply for your IMS systems:
  • When you want to quiesce the catalog databases as part of the maintenance procedure, you must make sure that the maintenance for APAR PH18953 (PTF UI96746) is applied to all IMS systems. Next, you must issue the following command so that the MINVERS and CDSLID levels are set in DBRC and the quiesce process can be used:

    CHANGE.RECON MINVERS('15.1') CDSLID(3)

  • When your IMS environment includes multiple IMS catalog databases, you must assign unique alias names to the IMS catalogs to differentiate between the IMS catalogs. Next, run the Catalog Alias Names utility (DFS3ALI0) on the IMS system that has the APAR PH18953 (PTF UI96746) maintenance applied. This utility enables defining the catalog aliases in the IMS DBDLIB data set and the use of the DFSCD000 structure that the maintenance delivers to SDFSRESL.

    You can copy other catalog resources such as DFSCD000, DFSCX000, and DFSCP* from SDFSRESL to DBDLIB and PSBLIB as required. Alternatively, you can make sure that the IMS RESLIB, SDFSRESL, is included in the IMS DD concatenation for the ACBGEN step.

Considerations for implementing multiple catalog definition changes

When you apply maintenance for multiple APARs simultaneously, for instance, as part of a Recommended Service Upgrade (RSU), there might be changes to the catalog definition from the multiple APARs. In such cases, all the changes are applied to the resource definitions in IMS.SDFSRESL. If any of the APARs included a structural change, then you must use the structural change procedures for activation of these changes. Otherwise, you can use the non-structural change procedures. Each APAR might have a different post activation procedure. You must review the post activation procedures and implement as indicated in the RSU.

Recommendation

It is recommended that you run ACB Generation and Catalog Populate utility (DFS3UACB) for performance and simplicity reasons. However, you can also run the Application Control Blocks Maintenance utility (DFSUACB0) and Catalog Populate utility (DFS3PU00) separately.

Control cards for DFS3UACB step

The SYSIN DD control card for ACBGEN portion and the SYSINP control card for the populate portion of the ACB Generation and Catalog Populate utility (DFS3UACB) differ and depend on whether the IMS managed ACBs is implemented and whether the change is structural or non-structural.
Note: The information provided for the control cards for ACB Generation and Catalog Populate utility (DFS3UACB) is applicable to the equivalent control cards in the Application Control Blocks Maintenance utility (DFSUACB0) and the Catalog Populate utility (DFS3PU00), when you want to run these utilities separately instead of running the recommended ACB Generation and Catalog Populate utility (DFS3UACB).
Refer to the following table to understand the usage of the SYSIN DD and SYSINP control cards and the use of the BUILDPSB action for each of the scenarios listed:
Table 1. Control cards usage in various scenarios
Scenarios Non-Structural changes Structural changes
Managed ACB is enabled Managed ACB is not enabled Managed ACB is enabled Managed ACB is not enabled
Offline installation SYSIN or SYSINP is not specified SYSIN or SYSINP is not specified In SYSINP specify:MANAGEDACBS=(UPDATE,UNCOND) and use the DFS3PU00 utility In SYSIN DD, specify: BUILD DBD=(DFSCD000,DFSCX000)
Online installation SYSIN or SYSINP is not specified SYSIN or SYSINP is not specified In SYSINP specify: MANAGEDACBS=(UPDATE,UNCOND) if all IMS systems are enabled and use the DFS3PU00 utility. If not, in SYSINP DD, specify: MANAGEDACBS=(STAGE,CATRSCS) and use the DFS3PU00 utility In SYSIN DD, specify: BUILD DBD=(DFSCD000,DFSCX000)
Use of the BUILDPSB action Not required Not required Required Required

What to do next

After you review the prerequisite considerations and taken the necessary action, you can return to IMS Catalog maintenance procedures to refer to the procedures that you want to follow.