Re: RAID 5 vs RAID 10 benchmark

From: Jonathan Lewis <jonathan_at_jlcomp.demon.co.uk>
Date: Wed, 15 Dec 2004 08:08:24 +0000 (UTC)
Message-ID: <cpordo$5e7$1@hercules.btinternet.com>

Sorry about the delay in replying. Two weeks out of the country, and lots to catch up on.

I rarely get the numbers right, but a fixed parity disk is either RAID-3 or RAID-4. When you move to RAID-5, I believe the parity is described as 'block-level rotating parity', so every disc gets a fair share.

A pattern across five disc would look something like the following (where D = data and P = parity block).

D D D D P
D D D P D
D D P D D
D P D D D
P D D D D

-- 
Regards

Jonathan Lewis

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"Joel Garry" <joel-garry_at_home.com> wrote in message 
news:91884734.0411291559.5748e1b0_at_posting.google.com...


>

> Shouldn't the parity disk have a higher risk of failing because it is

> pounded on more heavily than the others?

>

> (Personally, I've seen two disks go out more than once, and haven't

> seen a parity disk go out alone, but I don't think what I've seen is

> representative.  But I do think a batch of disks manufactured together

> will be more like each other than like those from another batch.  And

> I've seen bad batches from IBM.)

>

> jg

> --

> @home.com is bogus.

> "...Another one of those block-rockin' beats!" - Chemical Brothers

Received on Wed Dec 15 2004 - 02:08:24 CST