Re: Methods to clone large production database

  • From: "Don Seiler" <don@xxxxxxxxx>
  • To: rjamya@xxxxxxxxx
  • Date: Wed, 28 Mar 2007 10:30:52 -0500

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 <rjamya@xxxxxxxxx> 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.


On 3/27/07, Allen, Brandon <Brandon.Allen@xxxxxxxxxxx> 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

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