From: Fergal Taheny <>
Date: Tue, 15 Nov 2011 23:33:51 +0000
Message-ID: <>

Hi Allen,
My understanding and experience is that raid 10 will be much faster for reads too because the data is mirrored and so reads can be done from both sides of the mirror and so read throughput is double that of a non mirrored stripe.

On 15 Nov 2011 22:53, "Allen, Brandon" <> wrote:

> I'm curious why your reads were so much faster on the RAID10. All else
> being equal, I'd expect to see the writes faster on RAID10 vs. RAID5 (once
> your cache is exceeded), but not the reads. I suspect there was something
> else affecting the numbers other than just the RAID level. As with pretty
> much everything else, the correct answer on the RAID5 vs. RAID10 question
> is - it depends.
> A couple other important factors that are often overlooked are that RAID5
> can only tolerate a single disk loss while RAID10 can survive multiple
> failures, and RAID10 will still perform well in the event of a failure but
> performance will be severely impacted on the RAID5 until it is repaired.
> Regards,
> Brandon
> -----Original Message-----
> From: []
> On Behalf Of Karl Arao
> apparently the RAID10 was 2x faster..
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Received on Tue Nov 15 2011 - 17:33:51 CST

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