Re: backup Restore

From: joel garry <joel-garry_at_home.com>
Date: Thu, 2 Sep 2010 08:59:03 -0700 (PDT)
Message-ID: <4d2a593e-9766-4d45-9897-89ea79dd9d7e_at_a17g2000yqi.googlegroups.com>

On Sep 1, 11:05 pm, Ruddy <reach..._at_gmail.com> wrote:
> i Just needed some tips.
>
> We have an oracle DB running on 8i in production system. Its has a
> standby which is getting synced using archive logs on a remote
> destination.
>
>                                 Archive Log
> Server A
> -----------------------------------------------------------------------------------------------
> Server B
>
> Server A and Server B are in 2 different locations.
>
> My doubt
>
> Can i have the following architecture , where archive logs are written
> to 2 servers ?
>
> Server
> A-------------------------------------------------------------------------------------------------
> Server B
> |
> |
> |
> Server C
>
> So in the above Server A is primary and i start to write archive logs
> to Server B remote location and Server C , same location as Server A.
>
> Then for testing purpose i now apply logs to Server B/Server C , so at
> a point in Time , as archive logs are applied , all my three servers
> Server A , Server B and Server C are having same data.

See the init.ora parameter log_archive_dest_n http://download-west.oracle.com/docs/cd/A87860_01/doc/server.817/a76961/ch180.htm#41715

Are you applying manually or automatically? If you are using the automatic application, there are things that could stop your production. Whatever the case, things are much better in supported versions.

>
> My second more important doubt is Can i make Server B primary and let
> it ship logs to Server C and Server A without having to take full
> backup of Server B? I heard from some guys that this is not possible
> but i am hoping that there would be some undocumented way to achieve
> this.

You can failover to server B... oh, you are asking whether you can make server A a standby after failover. There was a white paper about this on oracle.com, I don't know if it is still there. "Graceful Switchover and Switchback
Oracle Standby Database
Versions 7.3, 8.0, 8.1
Revised November 11, 1999"
You never know what you might find on the web, though.

The basic problem is you have to avoid a resetlogs operation to make this work. Activating a standby database implicitly does a resetlogs. Most unsupported hacks to avoid this will give you a corrupted database. The paper shows how to work around that by stopping the databases at the correct time and doing the correct manipulation of controlfiles and applying archived logs to avoid a resetlogs.

This requires a lot of careful testing.

>
> Please let me know.

jg

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Received on Thu Sep 02 2010 - 10:59:03 CDT