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Re: Methods to clone large production database

From: Don Seiler <>
Date: Wed, 28 Mar 2007 10:30:52 -0500
Message-ID: <>

Prior to RMAN, we would go tablespace-by-tablespace, putting them into BACKUP mode, then doing a gzip -c to copy and compress the datafiles on the fly. This was done to disk, and then that disk was copied to tape the next morning. The whole backup process took less than 3 hours on our ~750gb database, which we did in full every night. We could do restores for development by basically emulating a disaster recovery from one of the backups.

Now we're on RMAN on 10gR2, and a level 0 backup takes over 9 hours. I'm certain that I have some tuning to do, but we're living with doing one level 0 on Saturday night when we have an extended window without many users. The rest of the week we do a level 1 with block change tracking enabled, and it takes 20-40 minutes, which is very nice, and makes the 9 hour level 0 much more easier to swallow for now. As before, we backup to disk. I also then use rsync to push copies of the backup disk slab to our development server as well as a third box for safe-keeping.

For cloning, I run an RMAN "duplicate database" command. We have a retention policy of 7 days, so the developers can request a restore to any point in the last 7 days for their development instances.


On 3/27/07, rjamya <> wrote:
> we use raw files. take hot backup and create a create_controlfile. After the
> hot backup, we run multiple dd's over private network from one server to
> another. once those are copied (and renamed) over, we manipulate control
> file script and create the control file, and preform recovery to the scn.
> Along with data files, we also copy over archive logs to help in recovery.
> rjamya
> On 3/27/07, Allen, Brandon <> wrote:
> >
> >
> > What exactly is the "raw copy method"? Do you just mean that you put the
> database/tablespaces in backup mode and copy with the OS utilities? Or is
> it something to do with raw storage, in which case I didn't think you could
> use the OS copy utilities, but I'm not really sure since I've never worked
> with raw storage.
> >
> > Thanks,
> > Branddon

Don Seiler
Received on Wed Mar 28 2007 - 10:30:52 CDT

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