Backup and Recovery › Considerations for Recovery of Native VSAM Files

Considerations for Recovery of Native VSAM Files

About Recovery for Native VSAM Files

CA IDMS/DB performs journaling for native VSAM files just like it does for other types of files it supports. The recovery procedures described in this chapter apply to native VSAM files also. The processing difference is that the BACKUP and RESTORE utility statements cannot be used with native VSAM files. Instead, use IDCAMS or some other utility for backing up and restoring the file.

Potential Problems

Since VSAM controls the actual updating of the data sets, recovery problems may occur. If a total system failure occurs after CA IDMS/DB passes control to VSAM, automatic recovery is not guaranteed. Therefore, you should back up native VSAM data sets frequently, as described in the appropriate VSAM documentation. Recovery can then be accomplished by restoring your file Using IDCAMS (or some other utility) and ROLLFORWARD utility statements.

File Verification After Failure

If a DC/UCF system fails or a local mode application terminates abnormally, you must issue the IDCAMS VERIFY command for native VSAM files that were open for update at the time of the failure.

Limitations for ESDS Areas

You cannot use the ROLLBACK utility statement for an ESDS area to which a record has been added, because VSAM does not allow the necessary erase.

Limitations for KSDS Areas

Due to limitations within the VSAM access method, ROLLFORWARD and ROLLBACK cannot be run with the SORTED option to recover native VSAM KSDS areas. If you need to use the SORTED option, because of the volume of data, and a database that contains a mixture of KSDS, ESDS, and/or RRDS native VSAM files, follow these steps: