Sunday, February 17, 2008

RMAN, RAC, ASM, FRA and Archive Logs

The topic, as the title suggests, concerns RMAN, RAC, ASM and archive logs. This post is rather different than my prior posts, in that, I want to open up a dialogue concerning the subject matter. So, I’ll start the thread by posing a question: Are any of you that run RAC in your production environments backing up your archive logs to an FRA that resides in an ASM disk group (and of course backing up the archive logs to tape from the FRA)? Managing your free space within your FRA is paramount as are judicious backups of the FRA (actually these really go hand in hand). However, I am very interested in your experience. Have you come across and “gotchas”, bad experiences, positive experiences, more robust alternatives, extended solutions, etc.? Being somewhat of a backup and recovery junky, I am extremely interested in your thoughts. Let the dialogue commence!

Update: 03/26/2008

A colleague of mine has been doing some testing using RMAN, RAC, ASM, FRA for archive log management. Also, he has tested the integration of DataGuard into this configuration. To be more precise, he has tested using an FRA residing in an ASM disk group as the only local archive log destination. In addition to the local destination, each archive log is sent to the standby destination. Based on his testing this approach is rather robust. The archive logs are backed up via the "BACKUP RECOVERY AREA" command with a regular periodicity. This enables the FRA's internal algorithm to remove archive logs that have been backed up, once the space reaches 80% full. No manual intervention is required to remove the archive logs. Moreover, the archive logs in this configuration will only be automatically deleted from the FRA if both of the following are true: 1) the archive log has been backed up satisfying the retention policy and 2) the archive log has been sent to the standby. When there is a gap issue with the standby database, the archive logs are read from the FRA and sent to the standby. It works real nice!