From: Christoph Hellwig <hch@infradead.org>
To: mark delfman <markdelfman@googlemail.com>
Cc: Linux RAID Mailing List <linux-raid@vger.kernel.org>
Subject: Re: xfs > md 50% write performance drop on .30+ kernel?
Date: Tue, 13 Oct 2009 18:52:41 -0400 [thread overview]
Message-ID: <20091013225241.GA32197@infradead.org> (raw)
In-Reply-To: <66781b10910130406s4119985fg5db7679a2e9fd4f2@mail.gmail.com>
On Tue, Oct 13, 2009 at 12:06:24PM +0100, mark delfman wrote:
> A little more information which I ?think? seems to point at MD.....
>
> Creating an EXT3 FS on an MD RAID also shows a circa 50% performance drop.
> We have tried a multitude of RAID options (raid6/0 various chunks etc).
>
> Using a hardware based raid XFS / EXT3 shows no performance drop
> (although the hardware raid is significantly slower than MD in the
> first place)
>
> We are happy to keep testing and offering anything that could be
> useful, we are just a little stuck thinking of anything else to do....
Can you test with conv=direct added to the dd command lines? If that
shows the problems too it's probably writeback-related. If not the
problems must be somewhere lower in the stack.
next prev parent reply other threads:[~2009-10-13 22:52 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-10-12 16:58 xfs > md 50% write performance drop on .30+ kernel? mark delfman
2009-10-12 18:40 ` Richard Scobie
2009-10-13 1:33 ` Christoph Hellwig
2009-10-13 1:57 ` NeilBrown
2009-10-13 11:06 ` mark delfman
2009-10-13 11:09 ` Majed B.
[not found] ` <66781b10910130412x309d9de2l574ba12a9ed4100a@mail.gmail.com>
2009-10-13 11:15 ` Majed B.
2009-10-13 11:29 ` mark delfman
2009-10-13 14:30 ` Asdo
2009-10-13 15:13 ` mark delfman
2009-10-13 15:15 ` mark delfman
2009-10-13 22:52 ` Christoph Hellwig [this message]
2009-10-14 19:34 ` mark delfman
2009-10-27 10:28 ` Thomas Fjellstrom
2009-10-27 11:11 ` Thomas Fjellstrom
2010-01-02 6:54 ` fibre raid
2009-10-13 3:38 ` Richard Scobie
2009-10-13 10:21 ` Asdo
2009-10-13 10:34 ` Mikael Abrahamsson
2009-10-13 14:49 ` Asdo
2009-10-13 19:53 ` Richard Scobie
2009-10-13 21:52 ` mark delfman
2009-10-13 18:49 ` Greg Freemyer
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20091013225241.GA32197@infradead.org \
--to=hch@infradead.org \
--cc=linux-raid@vger.kernel.org \
--cc=markdelfman@googlemail.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.