Using the DBRC interface is optional. You can skip this step unless you use DBRC (Database Recovery Control) and are running MVS with IMS Release 4.1 or above. Even if you are, this step is still optional.
The performance, ease-of-use, data compression and other attributes of CA Disk provide an alternative to using the IBM image-copy program for backing up IMS databases. The CA Disk backups can be written to disk, tape, or both and managed with the flexibility standard to all CA Disk backups. If you still want to use IBM image-copy. Putting the image copies on disk and then using the CA Disk Sequential Migration to Tape function to free the disk space can obtain benefits. The degree of operator intervention, primarily for tape handling, can be reduced significantly.
The purpose of the DBRC interface in CA Disk is to provide an automated means of notifying DBRC whenever CA Disk takes any action against a DBRC-registered data set. This includes the direct processing of database data sets themselves, such as in backup functions, or in moving IBM image-copy data sets that have been placed on disk.
If you activate the DBRC interface, CA Disk will extract the database names and their associated data sets from the DBRC RECON data set and keep the list in memory. When CA Disk is taking a backup (or archive) copy of one of these data sets, a control statement for the IBM DBRC update utility (program DSPURX00) is created to notify DBRC that a user image-copy has been taken. Similarly, the restore (or recover) functions generate control statements to notify DBRC that the recovery has been performed.
If you take IBM image-copy backups and place them on disk instead of tape, the Move/Copy and Sequential Migration to Tape functions can encounter them (intentionally or otherwise) and move them to new locations. Instead of extracting the database data set names as described above, these functions extract the image-copy records from the DBRC RECON data set. When an image-copy data set is moved, a control statement to change the volume list in the DBRC image-copy record is produced.
The DBRC utility program itself can be executed as either the last step of the job that produces the control statements, or later.
Since databases are often managed separately, it is desirable to supply the information as outlined in the next section, but only for the specific jobs designed to need it. Instead of making changes directly to the CA Disk JCL procedures and activating the support for all jobs, this information can be provided only for the specific jobs intended; for example, the database backup and recovery jobs.
The RECON data sets are dynamically allocated based upon the names provided in the IMS resident load library. CA Disk determines the current RECON data set and uses it. Alternatively, you can provide them in the JCL through //RECON1, 2 and 3 dd statements.
The generated control statements and any messages relating to the DBRC processing are printed in a separate output listing for easier review. //DBRCPRT is dynamically allocated for this purpose, but can be supplied in the JCL if desired. If it appears that the control statements are not being generated, supply the //RECONDMP in the JCL to produce a listing of the data sets from the RECON data set. Match the listing against the data sets processed by CA Disk. If the data set appears in both the listing and the CA Disk job, verify member DBRCDSNS of parmlib.
The control statements produced are of the following general format. For fast path databases with replication, messages are issued to indicate that CA Disk has processed an area data set. However, no control statements are produced. If the data set is given a new name when the backup copy is taken, the new name appears in the UDATA field.
For backup:
NOTIFY.UIC DBD(DBAHSP00) DDN(DBAHSP01) -
RUNTIME(862991635000) UDATA('*** DMS ***')
For recovery:
NOTIFY.RECOV DBD(DBAHSP00) DDN(DBAHSP01) - RCVTIME(862991635000) CURRENT
For migration of image-copy data sets:
CHANGE.IC DBD(DBAHSP00) DDN(DBAHSI01) - RECTIME(862671605243) VOLLIST(WRK800)
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