From: Richard Scobie <richard@sauce.co.nz>
To: linux-raid@vger.kernel.org
Subject: Re: Software RAID when it works and when it doesn't
Date: Wed, 17 Oct 2007 11:29:52 +1300 [thread overview]
Message-ID: <47153B60.5010008@sauce.co.nz> (raw)
In-Reply-To: <14526.1192571833@mdt.ecitele.com>
Mike Accetta wrote:
> is at the mercy of the low level disk driver. We've observed abysmal
> RAID1 recovery times on failing SATA disks because all the time is
> being spent in the driver retrying operations which will never succeed.
> Also, read errors don't tend to fail the array so when the bad disk is
> again accessed for some subsequent read the whole hopeless retry process
> begins anew.
This is one issue I believe the Western Digital RE/RE2 drives address.
The "TLER (time-limited error recovery)" feature limits retrys to try to
prevent this. I have the figure of 5 seconds in my head, but could be wrong.
Not sure if the Seagate nearline range offers the same sort of thing.
Regards,
Richard
next prev parent reply other threads:[~2007-10-16 22:29 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-10-13 18:40 Software RAID when it works and when it doesn't Alberto Alonso
2007-10-13 22:46 ` Eyal Lebedinsky
2007-10-13 22:50 ` Neil Brown
2007-10-14 5:57 ` Alberto Alonso
2007-10-16 21:57 ` Mike Accetta
2007-10-16 22:29 ` Richard Scobie [this message]
2007-10-17 21:53 ` Support
2007-10-18 15:26 ` Goswin von Brederlow
2007-10-19 7:07 ` Alberto Alonso
2007-10-19 15:02 ` Justin Piszcz
2007-10-20 13:45 ` Michael Tokarev
2007-10-20 13:55 ` Justin Piszcz
2007-10-26 16:11 ` Goswin von Brederlow
2007-10-26 16:11 ` Justin Piszcz
2007-10-23 22:45 ` Bill Davidsen
2007-10-24 5:50 ` Alberto Alonso
2007-10-24 20:04 ` Bill Davidsen
2007-10-24 20:18 ` Alberto Alonso
2007-10-26 16:12 ` Goswin von Brederlow
2007-10-26 17:09 ` Alberto Alonso
2007-10-27 15:26 ` Bill Davidsen
2007-11-02 8:47 ` Alberto Alonso
[not found] ` <471241F8.50205@harddata.com>
2007-10-14 18:22 ` Alberto Alonso
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