Invoking IPCS as a background job

Before you call IBM®, format the dump using the IPCS commands recommended by the appropriate procedure. Transferring a dump to IBM is often time consuming and some IPCS commands take time to run for a large dump. You can start an IPCS session before calling IBM. Then, during the call, the output can be browsed as needed.

Sometimes you might discover it is easier to create a second dump with a subset of the original dump. Send the second dump to IBM for initial diagnosis. For example, sometimes only the address spaces of the suspected problem job are necessary to diagnose system hangs. Of course, this is not always the case. If you do send a subset of the dump to IBM, do not delete the original dump.

Step for invoking IPCS as a background job

Usin the IPCS COPYDUMP subcommand to reduce the size of a very large dump, such as a stand-alone dump. An initial review of ASIDs 1-10 and others that are known to be involved in the problem greatly reduces the size and transfer time of the data set to be sent to the support center for initial diagnosis.

Use COPYDUMP to extract the problem address spaces that you want to analyze. COPYDUMP always includes address spaces 1-4 in the new dump data set and any data spaces associated with the address spaces. Use the LISTDUMP subcommand to see the address spaces available in a dump data set.

The IPCS COPYDUMP subcommand can also copy a single unformatted dump from one data set to another. Use the following example JCL to guide your creation of a batch job that invokes IPCS as a background job. This job opens the dump and extracts the required ASIDs, using the IPCS COPYDUMP command, and saves the result in another data set.

Figure 1. JCL for invoking IPCS as a background job

//RLWG JOB '796634,?,S=I','RL WRIGHT',MSGLEVEL=(2,1),
// CLASS=2,NOTIFY=RLW,MSGCLASS=H                     
//IKJEFT01 EXEC PGM=IKJEFT01,REGION=4096K,DYNAMNBR=50
//SYSTSPRT DD SYSOUT=*                               
//SYSTSIN DD *                                       
IPCS DEFER NOPARM                                    
COPYDUMP INDSNAME('IPCS1.SYSOS18.SV03235') +         
  OUTDSNAME('IPCS1.SYSOS18.SV03235.SUBSET') +        
  ASIDLIST(1:10,15) SPACE(15000 10000) +            
  NOCONFIRM                                          
END

The options on the example for Figure 1 are:

DEFER: Defers the use of a dump directory. In this example COPYDUMP had no need for the dump directory.
NOPARM: Indicates not to use an IPCSPRnn parmlib member. This eliminates the allocation of the problem and data set directories named by IPCSPR00 on the production system.