Symptoms:
An abend in L-Serv can cause the corruption of a file when LDMAMS is processing a COMPRESS. How can this be prevented?
Environment:
The CA L-Serv LDMAMS Utility executing in a z/OS enviroment.
Cause:
The LDMAMS COMPRESS has been interrupted which corrupts the partially rebuilt VSAM file.
The root cause of such situation can be an Abend in L-Serv or an external access to the dataset that is currently compressed.
Resolution:
It is recommended to backup a file before running a COMPRESS. This is also recommended when using LDMAMS utility within LServ.
Here is the best practice sequence to COMPRESS a VSAM dataset including a BACKUP:
1 - Run a LDMAMS step for each VSAM you need to COMPRESS.
2 - Add a LDMAMS Backup/COPY command before the COMPRESS command. The COMPRESS will start if the LDMAMS Copy completed successfully.
The SYSIN contains the commands :
REPRO INFILE(PRODKSDS) OUTFILE(KSDSBKP) REPLACE REUSE
COMPRESS INFILE(PRODKSDS) WORKFILE(PRODCOPY)
Note : Options REPLACE and REUSE may be coded in case KSDSBKP is not empty.
If the REPRO failed LDMAMS won't execute the command COMPRESS but will issue message :
'LDM0811E Statement skipped due to previous error'
This way, the REPRO allows to check that the KSDS is ready for the compress.
Additional Information:
For further information, please see "Maintain Managed Files" in the CA-L-Serv Chapter found in the CA Common Services Administration Guide