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From: Ian Pilcher <arequipeno@gmail.com>
To: linux-raid@vger.kernel.org
Subject: Small chunk size read performance penalty
Date: Sun, 18 Aug 2013 17:05:01 -0500	[thread overview]
Message-ID: <kurge6$qi0$1@ger.gmane.org> (raw)

Can anyone point me to a good explanation of the read performance impact
of small (RAID-5 and RAID-6) chunk sizes?

I understand why large chunks hurt write performance, but I haven't been
able to reason through the small-chunk/read case, and my Interweb
searches haven't really turned anything up.

The "read penalty" is definitely there; I can see it in the test data
from my NAS.  I just don't understand *why* it's there.

Thanks!

-- 
========================================================================
Ian Pilcher                                         arequipeno@gmail.com
Sometimes there's nothing left to do but crash and burn...or die trying.
========================================================================


             reply	other threads:[~2013-08-18 22:05 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-08-18 22:05 Ian Pilcher [this message]
2013-08-18 22:16 ` Small chunk size read performance penalty Roberto Spadim
2013-08-19  1:40 ` Stan Hoeppner
2013-08-19  5:49   ` Ian Pilcher
2013-08-20  2:28     ` Stan Hoeppner
2013-08-19  3:01 ` Roberto Spadim

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