Introduction of IBM DB2 Archive logging leveraged by Avamar DB2 plugin

Article Number: 504655 Article Version: 3 Article Type: How To

Avamar Plug-in for IBM DB2 7.4.101-58,Avamar Plug-in for IBM DB2 7.3.101-125,Avamar Plug-in for IBM DB2 7.5.100-183

The intention of this article is introducing DB2 Archiving logging function, which will be leveraged by Avamar DB2 backup.

Archive logging is used specifically for rollforward recovery. Archived logs are log files that are copied from the active log path to another location. You can use one or both of the logarchmeth1 or logarchmeth2 database configuration parameters to allow you or the database manager to manage the log archiving process.

Active and archived database logs in rollforward recovery. There can be more than one active log in the case of a long-running transaction.

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Taking online backups is only supported if the database is configured for archive logging. During an online backup operation, all activities against the database are logged. When Avamar online backup is restored, the logs must be rolled forward at least to the point in time at which the backup operation completed. For this to happen, the logs must be archived and made available when the database is restored. After Avamar online backup is complete, the database manager forces the currently active log to be closed, and as a result, it will be archived. This ensures that Avamar online backup has a complete set of archived logs available for recovery.

The logarchmeth1 and logarchmeth2 database configuration parameters allow you to change where archived logs are stored. The logarchmeth2 parameter enables you to archive log files to a second separate location. The newlogpath parameter affects where active logs are stored.

Unless you specify that you want to manage the active logs (by using the LOGRETAIN value), the database manager removes log files from the active log path after these files are archived and they are no longer needed for crash recovery. If you enable infinite logging, additional space is required for more active log files, so the database server renames the log files after it archives them. The database manager retains up to 8 extra log files in the active log path for renaming purposes.


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