Corruption of rman backups
Date: Fri, 26 Jun 2009 15:29:04 +1000
I've just come across this problem and thought I'd share it.
I recently attempted to set up a standby database from an rman backup of a production database.
The database restored ok, but when doing a recover I got an ORA-600 [kddummy_blkchk].
After working through the errors with a guy from Oracle support (who incidentally was very helpful), it turned out that the SYSAUX tablespace was corrupted after the restore - even though the source DB had no corruption. There was no indication of the corruption during processing of the 'restore database' directive. This of course makes the recovery process at best difficult, and for an rman noob like me, impossible.
It turns out that this is a 'known bug' with rman using compressed backup sets. The bug number is 7041254. A patch is available - at least for our architecture.
The bug reads as though the problem is quite innocuous - basically just that 'restore validate check logical' fails. You might look at that and say no big deal, I'm only validating the backup. However, what it doesn't say is that if you restore that backup, you will have corrupt blocks in your SYSAUX tablespace.
Note that this is only if you are using compressed backup sets.
I apologize if posting this information is forbidden, but I would have very upset if I hadn't known about this until I was actually restoring a production database - for real, so I thought I'd share the information. As far as I know, Oracle have not.
This email is intended solely for the use of the addressee and may contain information that is confidential, proprietary, or both. If you receive this email in error please immediately notify the sender and delete the email. Received on Fri Jun 26 2009 - 00:29:04 CDT