From: Richard Scobie <richard@sauce.co.nz>
To: Arkadiusz Miskiewicz <a.miskiewicz@gmail.com>,
Linux RAID Mailing List <linux-raid@vger.kernel.org>
Subject: Re: software raid rebuilding and O_DIRECT access (xfs_repair) slowness
Date: Fri, 02 Oct 2009 07:30:41 +1300 [thread overview]
Message-ID: <4AC4F551.2080606@sauce.co.nz> (raw)
In-Reply-To: <200910011949.42542.a.miskiewicz@gmail.com>
Arkadiusz Miskiewicz wrote:
> The question is now why software raid is soo slow when device is accessed with
> O_DIRECT by xfs_repair? (that's hch guess on what's the problem). Is this bug,
> expected behaviour?
I would think that this is not unexpected - 2 disk bound tasks, one
(resync), which requires the heads to sequentially step cylinder by
cylinder from the beginning to the end.
The other, xfs_repair, which is randomly seeking all heads all over the
platters.
Regards,
Richard
prev parent reply other threads:[~2009-10-01 18:30 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-10-01 17:49 software raid rebuilding and O_DIRECT access (xfs_repair) slowness Arkadiusz Miskiewicz
2009-10-01 18:30 ` Richard Scobie [this message]
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