Re: ASM diskgroup redundancy

From: Jörg Jost <>
Date: Sun, 18 Sep 2011 03:38:56 -0700 (PDT)
Message-ID: <>

On 7 Sep., 15:28, Mladen Gogala <> wrote:
> Why would I need
> to waste CPU on ASM mirroring when the company has already paid for the
> device that can do it automatically, with its own CPU?


we use the mirroring feature delivered by ASM at two sites. And we do this most of all because of saving money :)

Think about a two node RAC, each node sitting in a separate data center at
the same building, but in different rooms because of security reasons. Fire or water
will destroy normally only one site (hopefully)

So, regarding this scenario, you will normally use two storages, one for each data center.

Now you have the choice, use the ASM mirroring feature to make all mirroring over both
storages or use some build in feature delivered by the storage manufacturer. Last one will
often cause expensive investments, because this feature is not cost free.

In this case we use ASM mirroring with two failure group, one on each storage. So we have
no single point of failure.


Joerg Received on Sun Sep 18 2011 - 05:38:56 CDT

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