RE: Oracle RAC and SSD

From: Mark W. Farnham <>
Date: Tue, 26 May 2015 14:34:23 -0400
Message-ID: <04b601d097e2$97263110$c5729330$>

Tim is quite correct for the large bulk of storage objects that must be sharable for RAC.

There are a few types of storage in RAC that can be mounted RW on one host and R(ead) only on the other hosts in a RAC configuration even though they are technically local storage. Your mileage may vary depending on OS, network software, and wiring.

Figuring all that out so that nothing bites you in the as-, er, hindquarters is not quantum physics but needs to be tightly correct. If any of the storage might need to be readable when the local host it is plugged into is down, you will need some alternate wiring available for high availability security, if for example, you need to research log and out messages from a down node or to apply written local redo log information from another node.

Oracle likely would opine they do not support such configurations, in the sense that if you have a problem with it they are not going to figure it out for you (as opposed to the sense that if you do it your environment is totally unsupported; it is probably a good idea to keep sufficient free acreage on your array to migrate anything you have local should a support issue arise.)

There may be opportunities in various configurations to save money for online and archive redo locations as well as log and out, possibly saving internode network bandwidth, reducing latency, and de-heating the shared disk farm (including its network attachment).

Whether the custom engineering is worth the effort is a very debatable topic. I'd have my doubts that things like automated restarts from OEM would routinely work.


-----Original Message-----
From: [] On Behalf Of Tim Gorman Sent: Tuesday, May 26, 2015 1:32 PM
Subject: Re: Oracle RAC and SSD

The questions are the same as with HDD.

Is the SSD shared (on a SAN?) or is it locally-mounted on the RAC nodes?

If the former, then yes. If the latter, then no.

On 5/26/15 10:51, Ali Alizadeh wrote:
> Can we user SSD with oracle RAC (ASM) as a replacement to SAN?
> Regards,
> Ali


Received on Tue May 26 2015 - 20:34:23 CEST

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