ABCs of z/OS System Programming Volume 3 - IBM Redbooks

Aliases to the catalog can be defined if you use DFSMSdss, DFSMShsm, or if you specify
ALIAS on the IMPORT command. If you have not deleted and redefined the catalog, all existing
aliases are maintained, and any aliases defined in the backup copy are redefined if they are
not already defined.
Lock the BCS before you start recovery so that no one else has access to it while you recover
the BCS. If you do not restrict access to the catalog, users might be able to update the
catalog during recovery or maintenance and create a data integrity exposure. The catalog
also will be unavailable to any system that shares the catalog. You cannot lock a master
catalog.
After you recover the catalog, update the BCS with any changes which have occurred since
the last backup, for example, by running IDCAMS DEFINE RECATALOG for all missing entries.
You can use the access method services DIAGNOSE command to identify certain
unsynchronized entries.
The Integrated Catalog Forward Recovery Utility
You also can use the Integrated Catalog Forward Recovery Utility (ICFRU) to recover a
damaged catalog to a correct and current status. This utility uses SMF records that record
changes to the catalog, updating the catalog with changes made since the BCS was backed
up. The SMF records are used by ICFRU as a login database. Use ICFRU to avoid the loss of
catalog data even after recovery.
Recovery step by step
Follow these steps to recover a BCS using the IDCAMS IMPORT command:
1. If the catalog is used by the job scheduler for any batch jobs, hold the job queue for all job
classes except the one you use for the recovery.
2. Lock the catalog using the IDCAMS ALTER LOCK command.
3. Use ICFRU to create an updated version of your last EXPORT backup.
4. Import the most current backup copy of the BCS (which contains the BCS's aliases as
they existed when the backup was made). For example, use this JCL:
//RECOVER EXEC PGM=IDCAMS
//BACKCOPY DD DSN=BACKUP.SYS1.ICFCAT.PROJECT1,DISP=OLD
//SYSPRINT DD SYSOUT=A
//SYSIN DD *
IMPORT INFILE(BACKCOPY) -
OUTDATASET(SYS1.ICFCAT.PROJECT1) -
ALIAS -
LOCK
5. If you did not run step 3, manually update the catalog with the changes made between the
last backup and the time of error, for example by using IDCAMS DEFINE RECATALOG.
6. Use IDCAMS DIAGNOSE and EXAMINE commands to check the contents and integrity of the
catalog (see 6.15, “Checking the integrity on an ICF structure” on page 357).
7. If the catalog is shared by other systems and was disconnect there for recovery, run
IDCAMS IMPORT CONNECT ALIAS on those systems to reconnect the user catalog to the
master catalog.
8. Unlock the catalog using IDCAMS ALTER UNLOCK.
9. Free the job queue if you put it on hold.
For further information about recovery procedures, see z/OS DFSMS: Managing Catalogs,
SC26-7409. For information about the IDCAMS facility, see z/OS DFSMS Access Method
Services for Catalogs, SC26-7394.
356 ABCs of z/OS System Programming Volume 3