RE: Voting Disks and OCR on 11.2.0.2
Date: Wed, 21 Nov 2012 17:19:54 +0000
Message-ID: <EC65ECF8123FEE4D8FC5B212637C30400165DCE587D2_at_EXCH1.morrisonsplc.co.uk>
I agree entirely Jed - I am happy with external redundancy as I accept the storage layer provides redundancy, however for such things as voting disks and redo logs (which are both very small relative to overall database sizes) then I would certainly advocate mirroring whenever possible.
John
www.jhdba.wordpress.com
-----Original Message-----
From: oracle-l-bounce_at_freelists.org [mailto:oracle-l-bounce_at_freelists.org] On Behalf Of Walker, Jed S
Sent: 19 September 2012 16:56
To: cichomitiko_at_gmail.com; Zabair Ahmed
Cc: oracle-l_at_freelists.org
Subject: RE: Voting Disks and OCR on 11.2.0.2
I wouldn't rely on the storage mirroring for the voting disk. I would have it redundant within Oracle also - as you would for controlfiles, online redo logs, etc. I have seen it happen before where a flaw in the mirroring technology resulted in the loss of a file. The system had been created with single online redo logs because the disk was mirrored, but the mirroring failed and the database failed with it.
-----Original Message-----
From: oracle-l-bounce_at_freelists.org [mailto:oracle-l-bounce_at_freelists.org] On Behalf Of Radoulov, Dimitre
Sent: Wednesday, September 19, 2012 5:07 AM
To: Zabair Ahmed
Cc: oracle-l_at_freelists.org
Subject: Re: Voting Disks and OCR on 11.2.0.2
On 19/09/2012 12:58, Zabair Ahmed wrote:
> So, back to my original question. Do I have a single point of failure?
> I have single raw/block device LUN which is configured within ASM as
> an ASM diskgroup (ASMSYS) with EXTERNAL REDUNDANCY to hold a single
> Voting Disk. At the SAN level I am told by the sysadmin that it's
> either RAID 1 or RAID 5.
>
So it appears that your single voting disk is on a mirrored LUN (RAID 1 or 5), I don't consider this a single point of failure.
Regards
Dimitre
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