From: John Robinson <john.robinson@anonymous.org.uk>
To: Goswin von Brederlow <goswin-v-b@web.de>
Cc: David Cure <lnk@cure.nom.fr>, linux-raid@vger.kernel.org
Subject: Re: max number of devices in raid6 array
Date: Mon, 17 Aug 2009 17:06:55 +0100 [thread overview]
Message-ID: <4A89801F.5050907@anonymous.org.uk> (raw)
In-Reply-To: <87zla44e9a.fsf@frosties.localdomain>
On 13/08/2009 03:52, Goswin von Brederlow wrote:
[...]
> I would take that with a verry large pinch of salt. From the little
> experience I have that value doesn't reflects reality.
You're probably right, given that the data error rate hasn't dropped (it
might have grown, given the higher areal densities, but in fact it's
been about 1 in 10^15 for a while) while drive size has grown.
While I was looking at the IDEMA LBA standard stuff, I found their paper
about long sectors (also discussed here recently) which features a wee
graph of hard drive capacity vs rebuilds before data loss in a 7-drive
RAID-5 with 512-byte sectors, showing about 450 rebuilds for 36G drives
but only 10 for 1.5T drives. See page 9:
http://www.idema.org/_smartsite/modules/local/data_file/show_file.php?cmd=download&data_file_id=1779
Cheers,
John.
next prev parent reply other threads:[~2009-08-17 16:06 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-08-12 9:06 max number of devices in raid6 array David Cure
2009-08-12 9:38 ` John Robinson
2009-08-12 12:19 ` David Cure
2009-08-12 14:53 ` Goswin von Brederlow
2009-08-12 16:27 ` Billy Crook
2009-08-12 16:33 ` John Robinson
2009-08-13 2:52 ` Goswin von Brederlow
2009-08-13 3:39 ` Guy Watkins
2009-08-14 3:40 ` Leslie Rhorer
2009-08-17 7:31 ` Goswin von Brederlow
2009-08-13 4:22 ` Richard Scobie
2009-08-17 16:06 ` John Robinson [this message]
2009-08-17 16:09 ` John Robinson
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