From: NeilBrown <neilb@suse.de>
To: "Cal Leeming [Simplicity Media Ltd]"
<cal.leeming@simplicitymedialtd.co.uk>
Cc: linux-raid@vger.kernel.org
Subject: Re: Curious problem with asynchronous RAID1 rebuild operations
Date: Tue, 5 Jul 2011 10:34:04 +1000 [thread overview]
Message-ID: <20110705103404.0ed0e9bb@notabene.brown> (raw)
In-Reply-To: <CALvtuFQ_c_-8DqKGaTV6LjL0JXC=8VKPKyx5U1Be49fepLcWzg@mail.gmail.com>
On Sat, 2 Jul 2011 12:07:54 +0100 "Cal Leeming [Simplicity Media Ltd]"
<cal.leeming@simplicitymedialtd.co.uk> wrote:
> Hi all,
>
> I tried to rebuild/sync two RAID1 arrays at the same time, with strange results.
>
> When a new drive was added into md0, it started to sync fine at
> 123,000kb/sec. Whilst that was running, I also added a new drive into
> md1, and this causes both arrays sync speed to slow down to
> 20,000kb/sec. I checked the /proc/sys/dev/raid/speed_limit_{min|max}
> and these were both set fine.
>
> I removed the drive from md1, and the md0 sync went back to the normal speed.
>
> RAID Setup:
> md0 - 2 drives (2TB Western Digital)
> md1 - 2 drives (500GB M3 SDD)
>
> So my question is, does anyone know why the sync speed (on all arrays)
> slowed down to almost 6-7 times the norm, when two (or more?) sync
> operations are taking place?
>
Dodgy controller? I assume both arrays are on the same controller.
Can you plug in a separate controller even if only temporarily and see what
happens?
I can see how any interaction with md would have this effect.
NeilBrown
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next prev parent reply other threads:[~2011-07-05 0:34 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-07-02 11:07 Curious problem with asynchronous RAID1 rebuild operations Cal Leeming [Simplicity Media Ltd]
2011-07-05 0:34 ` NeilBrown [this message]
2011-07-05 10:52 ` Cal Leeming [Simplicity Media Ltd]
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