Re: DR with ASM

From: Ram Raman <>
Date: Mon, 10 May 2010 21:49:03 -0500
Message-ID: <>

Thanks Harel and Freek.

What I would like to do is devise a strategy using this replication. We have SAN admins who will do the splitting part. Our backups go to ASM.

  1. I would like to bring up the DB at the DR site and do recovery without involving the RMAN backups, but using SRDF only.
  2. I would *also* like to test the RMAN backups at the DR site.

Only thing this is that the DR site will be a non RAC, single node Oracle install. We have been told to have a non RAC at the DR. We will be installing single node Oracle binaries on the DR site before hand. With the single node restriction, I am not sure if we can do #a. I was checking online and I found this paper: I think the closest to my case might be case 4. Will I be correct in saying these will be the steps:

  1. Install Oracle binaries (first time only)
  2. Bring up the ASM instance. where would the backup of ASM spfile be, if the backups go to ASM itself.
  3. Once ASM comes up, locate the latest controlfile backup for the DB and then restore spfile and controlfile and finally restore DB. The DB backup has been setup with Enterprise manager.

I have not done ASM restores using SRDF/S. That is the reason I am looking for some guidance. Thanks.

2010/5/8 Harel Safra <>

> (sending again - over quoting)
> Freek,
> The OP stated that he's using synchronous replication.
> In such a replication a bit is not acknowledged as written to the storage
> array until it was written to both the local and the remote storage array
> (perhaps only to the cache).
> Since the same write ordering is preserved the scenario in which the main
> site fails should be the same as a server crash, i.e. oracle will do crash
> recovery when you start up the server in the backup site. So synchronous
> replication **should** be just as robust as server failure.
> To test the "should" part, maybe a better way will be a forced split of the
> SRDF/SAN copy pair and then startup the database and ASM.
> Harel Safra
> On 08/05/2010 13:45, D'Hooge Freek wrote:
> Harel,
> Maybe a bit off topic, but can you say that such a procedure is really a realistic DR procedure?
> When you have a real disaster, the replication would be suddenly disrupted, so maybe a better test would be to disconnect the two storage boxes (not even stopping the replication gently).
> I'm wondering if this type of replication offers a bullet proof disaster recovery solution.
> It seems to me as being very vurnable to ASM corruption.
> regards,
> Freek D'Hooge
> Uptime
> Oracle Database Administrator
> email:
> tel +32(0)3 451 23 82
> disclaimer:
> _______________________________________

Received on Mon May 10 2010 - 21:49:03 CDT

Original text of this message