From: NeilBrown <neilb@suse.de>
To: Marcus Sorensen <shadowsor@gmail.com>
Cc: linux-raid <linux-raid@vger.kernel.org>
Subject: Re: raid device gone underneath array
Date: Mon, 22 Oct 2012 09:19:21 +1100 [thread overview]
Message-ID: <20121022091921.33f78a22@notabene.brown> (raw)
In-Reply-To: <CALFpzo4gLGzGWLRdVK7bZnYr3hbR7xOgn402UTP2_7UpRE8j6g@mail.gmail.com>
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On Thu, 18 Oct 2012 18:01:34 -0600 Marcus Sorensen <shadowsor@gmail.com>
wrote:
> I've been using software raid to mirror two devices, and recently one
> of the drives went AWOL.
>
> md1 : active raid1 sdm[0] sdc[1](F)
> 12884900728 blocks super 1.2 [2/1] [U_]
> bitmap: 1/96 pages [4KB], 65536KB chunk
>
> However, md1 froze, and in looking at the logs I saw this:
>
> Oct 18 17:47:48 sys kernel: md: cannot remove active disk sdc from md1 ...
> Oct 18 17:47:48 sys kernel: md: cannot remove active disk sdc from md1 ...
>
> [root(marcus)@sanmirror3-01 ~]# mdadm --manage /dev/md1 --remove /dev/sdc
> mdadm: cannot find /dev/sdc: No such file or directory
>
> /dev/sdc was already gone! The /sys/block was already removed, no
> reference to it in /proc/scsi/scsi. So md1 was destined to sit there
> forever. So I rebooted and started up the degraded array.
These messages imply that 'sdc' was sent a request and no reply has been
received. Until the count of pending requests hits zero, md cannot
completely release sdc, and if it was a write - cannot reply to the request
that it received from a files system.
When a device fails or disappears the driver should ensure that all pending
requests fail - and return that failure status. md depends on this.
So - assuming this status continued for more than a minute - it looks like a
bug with the driver for 'sdc'.
NeilBrown
>
> Using kernel 3.6.2 from kernel.org
> --
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prev parent reply other threads:[~2012-10-21 22:19 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-10-19 0:01 raid device gone underneath array Marcus Sorensen
2012-10-19 0:24 ` Adam Goryachev
2012-10-19 4:03 ` Chris Dunlop
2012-10-19 4:22 ` Brad Campbell
2012-10-19 4:29 ` Chris Murphy
2012-10-19 15:45 ` Marcus Sorensen
2012-10-21 22:19 ` NeilBrown [this message]
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