Re: Duplicating from copy of a standby with standby controlfile

From: Mark Burgess <mark_at_burgess-consulting.com.au>
Date: Tue, 11 Feb 2014 09:29:55 +1100
Message-ID: <etPan.52f952e3.1bbbb921.40b2_at_bscosx02.local>

We do this with a combination of ZFS snapshots and clones from the standby database - no backupsets as such.

The method we have implemented to have the correct controlfile in place is:

1. Stop media recovery on the standby database.
2. Take the ZFS snapshot and clone of the relevant file systems.
3. Mount the snapshot database - this needs the control_files parameter pointing to the location of the clone file system.
4. Rename the redo logs - SQL script does this.
5. Rename the datafiles - we use RMAN to catalog the datafile copies and then do a switch to copy.
6. Backup the existing controlfile and restore the controlfile <— this is the important bit as it gives you a normal control file and not a standby controlfile.
7. Recover until cancel on the database using backup controlfile.
8. Open database with reset logs.

I have this scripted up - the database piece is independent of the method used to provide the copy of the datafiles.

I can send through the scripts if you are interested.

Regards,

Mark Burgess

On 11 February 2014 at 8:39:13 am, Don Seiler (don_at_seiler.us) wrote:

OK I've played a little more with the duplicate steps (using target-less duplication with BACKUP LOCATION specification) and so far it seems to only work with backups, not with datafile copies. I'd like to keep using the datafile copy method as it saves time, and our database is nearly 25Tb. Creating a "backup as copy" of the database and remounting the disks saves us from having to backup and then restore the datafiles which would take far too much time.

Like I said, this method works great but so far requires a primary controlfile. It's really only an extra step when we do the refresh from the standby side but I'd like to see if we can do it without having to do that step, just to simplify and script as much as possible.

On Sat, Feb 8, 2014 at 1:46 PM, Don Seiler <don_at_seiler.us> wrote: Version is 11.2.0.3. I'll explore the duplicate options. Anyone done it with data file copies target than backup set? I'd rather not do active our require connection to primary or standby other than the initial backup as copy.

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Received on Mon Feb 10 2014 - 23:29:55 CET