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Re: Clarion CX500 or Sun StorEdge 6920 Storage solution

From: Carel-Jan Engel <>
Date: Fri, 20 May 2005 19:06:06 +0200
Message-Id: <>

Other advantages of Data Guard are the ability to DELAY the application of the redo, providing you the DELAY time window to recover from (human) errors by setting the database in Read Only mode. Disadvantage of storage replication is that it requires far more bandwith. You will replicate any change to the redo members (both of them, depending on the granularity of your setup), plus all changes in redo/data/temp etc. I have read it can be as much as 30 times the amount of bandwith, compared to DG, but I haven't tested that myself.

Either you go asynchronous, or even the smallest write to a redo log file will cause complete blocks to be sent over again and again. (Most storage based replication uses the block or even track as the lowest level of granularity).

I'd go for Data Guard, but I might not be the most unbiased advisor on this topic ;-)

Best regards,

Carel-Jan Engel

If you think education is expensive, try ignorance. (Derek Bok) ===

On Fri, 2005-05-20 at 05:45, Matthew Zito wrote:

> I would go with the Clariion over the Sun box. While the Sun box has
> the advantage of being able to virtualize other companies' storage,
> it begs the question, "Why would you want to?". Also, Sun storage
> has a tradition of being terrible, especially early revs, and this is
> a rev 1 box at the moment. Beyond that, Sun's support for non-
> Solaris OSes is usually less than ideal, while EMC specializes in that.
> As far as the replication goes, data guard has the advantage that it
> won't propagate corruption to the far side. Storage based
> replication has the advantage that it can be synchronous even when
> the database is down on the far side, with no host CPU involvement.
> Pick your poison.....
> Thanks,
> Matt
> On May 19, 2005, at 3:50 PM, Wiegand, Jeff wrote:
> >
> > Good day.
> >
> > We're looking to make a decision on a SAN storage solution shortly. I
> > was wondering if anyone had any insights or preferences regarding
> > these
> > two products. We'll be using snapshot functionality to refresh our
> > dev,
> > qa, and stg environments. We're running with a high-available 3-
> > node RAC
> > with Data Guard solution on Windows, moving to Solaris this summer.
> > Our
> > standby is hosted at our facilities and production off-site, with a
> > hosting provider.=20
> >
> > We're also considering the possibility of using SAN replication
> > instead
> > of Data Guard. Is one product glaringly better than the other?
> >
> > Thanks,
> >
> > Jeff
> > --
> >
> >
> --

Received on Fri May 20 2005 - 13:10:50 CDT

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