DB2 Utility JCL

Every DB2 utility - LOAD, UNLOAD, REORG, RUNSTATS, COPY, RECOVER, CHECK DATA and CHECK INDEX - runs under the same program: DSNUTILB. This page shows the JCL skeleton that every utility job needs and what each DD statement does.

The DSNUTILB program

• DSNUTILB is the DB2 utility driver program. You run it with EXEC PGM=DSNUTILB.
• The PARM field has two parts: the DB2 subsystem name and a utility ID, for example PARM='DB2S,LOAD01'.
• The utility ID must be unique while the utility runs - DB2 uses it to track and restart the utility.
• STEPLIB must point to the DB2 SDSNLOAD library so the system finds DSNUTILB.
• The actual work to do is written as control statements in the SYSTSIN DD.

JCL DD statements of a utility job

• SYSTSIN holds the utility control statement, such as LOAD DATA ... or REORG TABLESPACE ....
• SYSREC (or SYSIN) is the input data set for LOAD, or the output data set for UNLOAD.
• SYSPRINT receives all utility messages - this is the first place to look when a job fails.
• SYSUT1 and SORTOUT are sort work data sets needed by LOAD, REORG and REBUILD INDEX.
• SYSDISC receives rejected rows from LOAD; SYSERR and SYSMAP are used for error and mapping information.
• COPYDDN data sets receive the image copies written by the COPY utility.

Monitoring and restarting utilities

• Use the -DISPLAY UTILITY(*) command to see every utility currently running on the subsystem.
• A failed utility can be restarted from its last checkpoint by resubmitting the same JCL with the same utility ID.
• Use -TERM UTILITY(utility-id) to terminate a stuck or failed utility before rerunning it cleanly.
• Never change the control statement between a failure and a restart - DB2 restarts from the recorded phase.
• Keep the SYSPRINT output of every utility run; it is the audit trail for production changes.

Example of a complete DB2 utility JCL:-