I have a 10.2.0.5 ASM instance that has been running happily since August 2012.
I have a backup policy with a retention policy of:
Retain backups that are necessary for a recovery to any time within the specified number of days (point-in-time recovery) - 7 days.
However, all my backups sets and archive logs are still in the RMAN repository.
I understood that ASM would delete the backups once they were no longer valid, based upon the retention policy.
I have now read in the Oracle documentation: Note that if you use a flash recovery area as your sole disk-based backup destination, then you never need to delete obsolete backups from disk. The automatic space management of the flash recovery area will keep files as specified by the backup retention policy, and then only delete them when space is needed.
I just wanted to check that as my FRA still has 20% free, this is why the old backups are not been deleted, and at some point the ASM trigger a delete when it needs more space.
Can anyone clarify this for me?
It is not the ASM instance that is going to remove any RMAN backup even in the flash recovery area (FRA).
If you are using FRA then it is the database instance that will check free space in FRA and delete obsolete backups if needed: this is the FRA "automatic space management".
There is some unfortunate wording use here in Oracle documentation:
- ASM (Automatic Storage Management) instance is managing disk groups and ASM disks as a database file system/volume manager
- FRA "automatic space management" has nothing to do with ASM instance and ASM resources: you can use FRA without ASM instance/ASM disk groups/ASM disks if you want.