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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

      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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