Re: RedHat 6 RAC Specific Questions & Concerns

From: Andy Colvin <acolvin_at_enkitec.com>
Date: Thu, 22 Aug 2013 22:27:15 -0500
Message-Id: <17DD4E23-583F-4549-8A24-2E1D3C5FA972_at_enkitec.com>

I've used MOS note #1062983.1 when recreating my ASM diskgroups - I haven't used it lately, but found it to be pretty reliable in the past (11.2.0.2 days). It covers the difference between 11.2.0.1 (crsctl start crs -excl) and 11.2.0.2+ (crsctl start crs -excl -nocrs), and gives the commands to recreate your CRS diskgroup, create a new generic spfile, and get the cluster back up and running. I strongly recommend creating a separate ASM diskgroup for your OCR and voting disks for one reason in particular. On most platforms running RAC/ASM, you will be using external redundancy. When creating OCR/voting disks in ASM on 11.2, the redundancy level of the diskgroup determines how many voting disks are created. External redundancy gets 1 voting disk, normal redundancy gets 3, high redundancy gets 5. It's generally a good idea to build out a small high redundancy diskgroup of 5 LUNs to provide the best protection. The loss of that LUN in external redundancy will take the node down. Losing one LUN in a high redundancy diskgroup will not affect the cluster at all.

Andy Colvin

Principal Consultant
Enkitec
andy.colvin_at_enkitec.com
http://blog.oracle-ninja.com

On Aug 20, 2013, at 2:34 AM, Martin Bach <development_at_the-playground.de> wrote:

> Hi Jeremy,
> this is an interesting thread. When you have a moment would you compare
> your notes against mine? Admittedly I didn't have to recreate the ASM
> instance
>
> http://martincarstenbach.wordpress.com/2011/10/13/the-tale-of-restoring-the-ocr-and-voting-files-on-linux-for-rac-11-2-0-2/
>
> Your comment about an ASM spfile backup is noted :) I have spent a
> little time yesterday with spget/spcopy in asmcmd and agree that there
> are some quirks with it. I believe a possible solution would be to use
> spbackup regularly in cron or similar to back the ASM spfile up. If you
> ever have to restore you use spcopy with the -u flag to update the gpnp
> profile. I found a few notes yesterday that explains the spfile/pfile
> steps-it's 1082943.1.
>
> Martin
> --
> Martin Bach
> Enkitec (The Exadata Experts)
> http://www.enkitec.com
> http://martincarstenbach.wordpress.com
>
>
> --
> http://www.freelists.org/webpage/oracle-l
>
>

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Received on Fri Aug 23 2013 - 05:27:15 CEST