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DFSMSrmm Catalog Synchronization Benefits

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Published on 24 December 2002, updated 21 October 2003

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IBM Form #: TIPS0122

Authors: Mary Lovelace

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    Since DFSMS/MVS V1.5 DFSMSrmm, Vital Record Selection (VRSEL) is enhanced by removing the need to perform catalog locates for all data sets that match to a WHILECATALOG VRS. The catalog status of data sets recorded by DFSMSrmm is now maintained dynamically during catalog and uncatalog operations.


    Running DFSMSrmm catalog synchronization

    The catalog synchronization function cannot be exploited until you enable it by synchronizing the DFSMSrmm control data set (CDS) with your user catalogs using EDGHSKP with PARM=CATSYNCH, and for unshared catalogs, enabling with EDGUTIL.

    The following enhancements are included:

    • How you enable catalog synchronization depends on your catalog environment. For fully shared catalogs, you can specify the CATSYSID(*) PARMLIB option and run EDGHSKP with PARM=CATSYNCH. For unshared catalogs you must specify CATSYSID(list of sysids) and run EDGHSKP with CATSYCNCH once per group of systems, and then enable synchronization using EDGUTIL UPDATE. The running of EDGHSKP with CATSYNCH is used to synchronize the DFSMSrmm control data set (CDS) with the available ICF catalogs. For full details refer to the DFSMSrmm Implementation and Customization Guide, SC26-7405.
    • Once the function is enabled, the VRS WHILECATALOG retention type, and the PARMLIB UNCATALOG option no longer rely on locate processing, but use the DFSMSrmm recorded catalog status. If the catalog status of a data set is unknown, VRSEL processing applies the CATRETPD retention period. Only after applying the CATRETPD retention period does DFSMSrmm treat the data set as non-cataloged. A locate is only issued during EDGHSKP CATSYNCH processing.
    • The LISTDATASET output and the report extract file data set record contain the catalog status as recorded by DFSMSrmm.
    • For environments with unshared catalogs you can run EDGHSKP CATSYNCH on a subset of catalogs by specifying the CATSYSID PARMLIB option.
    • For unshared catalog environments, EDGHSKP EXPROC return to scratch processing can now be run on a subset of volumes identified by the CATSYSID PARMLIB option.
    • LISTCONTROL CNTL can list the date and time the synchronization was last performed. The control dialog is also updated to show date and time.

    Tip: We recommend that you enable this function to improve the performance of the daily vital record and expiration processing.

    Before you can start catalog synchronization, you should check that DFSMSrmm has all the authorizations to read all ICF user catalogs including the tape volume catalog (TCDB). Normally, it is named SYS1.VOLCAT.VGENERAL.

    When you enable catalog synchronization, DFSMSrmm synchronizes the DFSMSrmm control data set and available user catalogs. Enabling catalog synchronization is normally a one-time action. Once the catalog is synchronized, DFSMSrmm continually tracks and updates the catalog status. You enable catalog synchronization by specifying the DFSMSrmm EDGRMMxx OPTION CATSYSID operand described in the DFSMSrmm Implementation and Customization Guide, SC26-7405, in the chapter “Defining System Options:OPTION.”

    Allocating a larger message data set

    You must allocate a larger DFSMSrmm message data set, because the catalog synchronization will write a record to the DFSMSrmm message file for each data set that is updated in the DFSMSrmm control data set.

    Journal considerations

    The catalog synchronization will also generate many records in the journal data set. Prepare for this by allocating a large journal data set, or process the catalog synchronization run with the journal data set disabled.

    Enabling catalog synchronization

    To request catalog synchronization, specify the CATSYNCH parameter. Before you start this function, check the size of your message data. The DFSMSrmm subsystem writes a message to this data set for each record that is updated in this run. You do not need to stop tape processing because this function can run in parallel to your normal jobs using tape drives. DFSMSrmm always retrieves catalog information to determine the catalog status of a data set.

    You must use CATSYNCH(YES) to indicate to DFSMSrmm that catalogs are synchronized when you run DFSMSrmm with unshared catalogs. Run EDGUTIL with the PARM=UPDATE parameter specified and CONTROL CATSYNCH(YES) to set the ’last catalog synchronization date and time’ in the DFSMSrmm control data set control record. Check that the catalog synchronization is enabled successfully by using the TSO RMM LISTCONTROL subcommand.


    Special Notices

    The material included in this document is in DRAFT form and is provided 'as is' without warranty of any kind. IBM is not responsible for the accuracy or completeness of the material, and may update the document at any time. The final, published document may not include any, or all, of the material included herein. Client assumes all risks associated with Client's use of this document.