Re: Rman question - recover after a delete obsolete?

"Dave" <shoad316_at_hotmail.com> wrote in message news:78cf0572.0403011422.d1c4d7_at_posting.google.com...
> Hi,
>
> Currently we backup our 8.1.7 and 9.2.0.2 databases using RMAN to
> disk. WE have a retention policy of 1. Since the filesystem is
> backed up to tape nightly, before we run the next backup we remove the
> old rman backup.
>
> Some of the DBA's run a delete obsolete in their nightly routine but I
> haven't because i'm not actually sure of the consequences. Lets say
> there's a problem and a user requests a copy of the database from 2
> weeks ago. If the retention was 1 and a delete obsolete was executed
> will we be able to recover using the catalog? My gut tells me no
> because were deleting all information about the backup from the
> catalog.
>
> I'd rather disable the retention policy within rman.. Then if we had
> to restore from a few weeks previous all you would have to do is run a
> crosscheck.
>
> We don't backup directly to tape, we don't have enough disk space to
> hold enough backups for the retention users require so we rely on the
> backup group's tape retention policy to satisfy our needs. So say
> nightly we run a backup, then a delete obsolete and 2 days from now
> need to restore, even tho we have restored the datafiles from tape
> will we be able to reocover? Would the recover process be different?
> Should we be marking backups as keep or disable the retention policy
> in rman?
>
> Thanks

Dave,

I will leave discussion of the retention policy to those better qualified. My comments are on how to do DELETE OBSOLETE and then recover from those 'deleted' backups.

According to p.2-53 of RMAN Reference (a96565.pdf), you cannot recatalog a backup piece or set that has been deleted. Thus once you do a DELETE OBSOLETE, the RMAN catalog can no longer know about those backup pieces and sets.

The other repository for RMAN information is the control file of the target database. My suggestion would be to follow the procedure in "Performing Recovery with a Backup Control File and No Recovery Catalog" on p.10-16 of RMAN User's Guide (a96566.pdf) and do an incomplete recovery using a backup of the control file taken after the backup of the database was done. Note that the user guide says that this control file backup has to be an AUTOBACKUP. Douglas Hawthorne Received on Thu Mar 04 2004 - 04:27:51 CST