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RE: Oracle replication with EMC2

From: Matthew Zito <>
Date: Tue, 18 Jul 2006 09:30:58 -0400
Message-ID: <>

There is a way to use SRDF in conjunction with BCVs on a Symmetrix to use for backups. Basically the Sym constantly replicates to the R2 (remote side), but there's a BCV attached to it. Whenever you want to test/open/backup the standby, you detach the BCV and do your business, then reattach.


Matthew Zito
Chief Scientist
GridApp Systems
P: 646-452-4090

-----Original Message-----
From: on behalf of Yechiel Adar
Sent: Tue 7/18/2006 8:35 AM
Subject: Re: Oracle replication with EMC2
Hello J B

SRDF is used for disaster recovery, not for backups.
If someone delete a datafile on the primary side it will also be deleted 
on the other side.
SRDF means that when EMC writes a block to the local disk it also send 
the block to a second EMC that writes them to the remote disks.
On the remote side you prepare a server, with oracle installed and 
oracle service defined for the database.
When you have disaster (preferably not :-) ) and the primary site is 
down, you go to the remote site and activate the backup server you keep 
Then you attach the EMC disk to the new server and bring up the instance.
The effect is like recovering after power failure.
You need of course to keep all the redo and database files and control 
files on the EMC for this to work.

AS I said this is not a backup option and you do not activate the remote 
site while the primary site is up.
You have an option to break the connection between the two sites and 
then bring the database on the remote site up while the primary is up.
The problem is that:
1) You lose all the updates if your primary goes down during this period.
2) You need to recopy all the database again when you reconnect.
So I will nor recommend this.

We use fiber to connect the two sites.
It handle without problems the workload of 100 branches of our bank, and 
that include an IBM mainframe plus hundreds of Windows servers.

Adar Yechiel
Rechovot, Israel

J B wrote:

> You replicate hot data files without putting them into hot backup
> mode or using rman? During periods of high database activity, I would
> have expected trouble starting up the remote site. Just like taking
> an OS backup of data files without telling oracle - sometimes it works
> but on high activity databases usually it doesn't work.
> Any performance issues with synchronous srdf?
> Thanks!
-- --
Received on Tue Jul 18 2006 - 08:30:58 CDT

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