Re: DataGuard vs Hardware mirroring for DR

From: Noons <wizofoz2k_at_yahoo.com.au>
Date: Thu, 19 Feb 2009 22:05:18 +1100
Message-ID: <gnje3t$duf$1_at_news.motzarella.org>



emdproduction_at_hotmail.com wrote,on my timestamp of 19/02/2009 9:44 AM:
> Dear Group,
>
> We are planning for DR site. We have two options, one is DataGuard,
> another is using Hardware SAN mirroring.
>
> Is there any pros and cons in terms of this two methods?

Of course there are.
Michel already pointed out a few important things. Let me jsut add a few more.

We have done mostly hardware SAN mirroring up to now, with sync replication. That's for both Oracle, Lotus Jokes and MS SQL.

But it's getting expensive: the volume keeps increasing and the pipe between the two sites is fixed capacity. That means we now need to upgrade it. And the cost for the upgrade is prohibitive.
So we are now looking at DataGuard: its main advantage is the volume that needs to be transferred across is much, much less than pure SAN-based sync writing.

Log shipping - the core technology around which DG evolved - is a lot less dependent on wide pipes than pure database page write-mirroring.

Like so many other things, it's all about cost-effectiveness.

Our experience so far is:

  • up to a certain volume, SAN mirroring can be cost effective and is certainly dirt easy to setup and get going.
  • after that, DG becomes more efficient, less costly and the cost of setup becomes justifiable.

What that point is, is highly dependent on your workload, data volume, setup, overall number of dbs on mirroring, etc. Received on Thu Feb 19 2009 - 05:05:18 CST

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