RE: SRDF and Oracle Rac 11gR2

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Date: Thu, 10 Apr 2014 20:55:22 +0000
Message-ID: <>

What we do is maintain 2 sets of disks on the DR side. One is always being synched, the second is occasionally broken off so we can bring the databases up for testing and is then brought back into synch when testing is complete.

But yes, that is point in time.

Jay Miller
Sr. Oracle DBA

From: [] On Behalf Of Matthew Zito Sent: Monday, January 27, 2014 4:33 PM
To: Andrew Kerber
Subject: Re: SRDF and Oracle Rac 11gR2

Again, it's been a long time, but you used to be able to split off a mirror periodically and open the database read-only or read-write, then shut it down and resync periodically (and the resync is obviously really fast if it's read-only).

But it's all point-in-time, and there's nothing comparable to active dataguard.


On Mon, Jan 27, 2014 at 4:29 PM, Andrew Kerber <<>> wrote: We are still in the evaluation phase, so I am trying to get the pros and the cons figured out. It does not sound like an SRDF standby can be opened in read only, though I could be wrong about that.

On Mon, Jan 27, 2014 at 3:18 PM, Matthew Zito <<>> wrote:

Well, so, this is the eternal debate, yeah? Data Guard offers infinite flexibility, the DBA can control everything, it's storage agnostic, you have lots of knobs to twiddle, so on some levels that's perfect.

On the flip side though, SRDF is application/OS agnostic. Anything that gets written to any SRDF'ed LUN, regardless of database, filesystem, OS, version, etc. ends up on the far side. Like magic.

And SRDF is freakishly stable and mature. It's been baked and stable for 15 years.

So SRDF is often best when you might have different database technologies, or different OSes, and you care about 100% reliability. It also removes responsibility from managing storage replication from the DBA team to some degree, since the array is responsible for pushing the bits around.

With regards to the complexity - once you've done a reference architecture, gotten it working once, you just repeat it over and over again. So that's a little bit of upfront effort, but I don't think in the long run it counts for much, especially compared with the care and feeding of DG.

So I don't see it as an easy call either way - if you have a lot of strong oracle skills in-house and want the flexibility, DG is the way to go. If you want to not have to deal with data protection and care about bulletproof reliability, or have a heterogenous environment, SRDF is great.


On Mon, Jan 27, 2014 at 4:08 PM, Andrew Kerber <<>> wrote: Yes, that makes sense. I've been looking at the EMC web site, and haven't really found anything definitive one way or another. It really sounds kind of tricky from what you are describing though, not sure I see a real advantage over dataguard at that point.

On Mon, Jan 27, 2014 at 3:44 PM, Andrew Kerber <<>> wrote: Has anyone used EMC's SRDF with Oracle RAC 11gR2? Any issues? Does it work with RAC?


Andrew W. Kerber

'If at first you dont succeed, dont take up skydiving.'

-- Received on Thu Apr 10 2014 - 22:55:22 CEST

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