From: Chris Webb <chris@arachsys.com>
To: "Majed B." <majedb@gmail.com>
Cc: Jon@ehardcastle.com, Goswin von Brederlow <goswin-v-b@web.de>,
Linux Raid Study <linuxraid.study@gmail.com>,
linux-raid@vger.kernel.org
Subject: Re: LVM and Raid5
Date: Wed, 16 Sep 2009 14:15:36 +0100 [thread overview]
Message-ID: <20090916131536.GA3752@arachsys.com> (raw)
In-Reply-To: <70ed7c3e0909160400k578741e7ue687d8fd983d0d12@mail.gmail.com>
"Majed B." <majedb@gmail.com> writes:
> I tested with both dd and hdparm, and in both cases, md0 proved to be
> much faster than the LV itself.
This is quite odd because usually an LVM2 logical volume is just a simple
linear device-mapper target onto the backing device. I could imagine a small
performance change but a large one really surprises me. Could there be
something going on here wrt sync vs non-sync IO?
Best wishes,
Chris.
next prev parent reply other threads:[~2009-09-16 13:15 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-09-16 8:22 LVM and Raid5 Linux Raid Study
2009-09-16 9:42 ` Jon Hardcastle
2009-09-16 10:09 ` Goswin von Brederlow
2009-09-16 10:20 ` Majed B.
2009-09-16 10:33 ` Jon Hardcastle
2009-09-16 11:00 ` Majed B.
2009-09-16 13:15 ` Chris Webb [this message]
2009-09-21 17:34 ` Goswin von Brederlow
2009-09-17 12:37 ` Michal Soltys
2009-09-21 14:33 ` [linux-lvm] " Mike Snitzer
2009-09-21 14:33 ` Mike Snitzer
2009-09-21 16:30 ` [linux-lvm] " Jon Hardcastle
2009-09-21 16:30 ` Jon Hardcastle
2009-09-21 17:26 ` [linux-lvm] " Mike Snitzer
2009-09-21 17:26 ` Mike Snitzer
2009-09-21 17:38 ` Linux Raid Study
2009-09-21 19:14 ` Majed B.
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