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Re: Oracle replication with EMC2

From: Yechiel Adar <>
Date: Tue, 18 Jul 2006 14:35:16 +0200
Message-ID: <>

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 there.
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 - 07:35:16 CDT

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