From owner-freebsd-stable@FreeBSD.ORG  Tue Feb 12 09:53:00 2008
Return-Path: <owner-freebsd-stable@FreeBSD.ORG>
Delivered-To: freebsd-stable@freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34])
	by hub.freebsd.org (Postfix) with ESMTP id DAED616A481
	for <freebsd-stable@freebsd.org>; Tue, 12 Feb 2008 09:53:00 +0000 (UTC)
	(envelope-from kris@FreeBSD.org)
Received: from weak.local (freefall.freebsd.org [IPv6:2001:4f8:fff6::28])
	by mx1.freebsd.org (Postfix) with ESMTP id 2C9FF13C467;
	Tue, 12 Feb 2008 09:52:59 +0000 (UTC)
	(envelope-from kris@FreeBSD.org)
Message-ID: <47B16C7B.1040803@FreeBSD.org>
Date: Tue, 12 Feb 2008 10:52:59 +0100
From: Kris Kennaway <kris@FreeBSD.org>
User-Agent: Thunderbird 2.0.0.9 (Macintosh/20071031)
MIME-Version: 1.0
To: Joe Peterson <joe@skyrush.com>
References: <47B0EA08.10202@skyrush.com> <47B0F117.4030105@FreeBSD.org>
	<47B0F406.6060206@skyrush.com>
In-Reply-To: <47B0F406.6060206@skyrush.com>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit
Cc: freebsd-stable@freebsd.org
Subject: Re: mount of ext2fs volume stuck in "D+" state (disk uninterruptible
 wait)
X-BeenThere: freebsd-stable@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: Production branch of FreeBSD source code <freebsd-stable.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-stable>, 
	<mailto:freebsd-stable-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-stable>
List-Post: <mailto:freebsd-stable@freebsd.org>
List-Help: <mailto:freebsd-stable-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-stable>,
	<mailto:freebsd-stable-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Tue, 12 Feb 2008 09:53:00 -0000

Joe Peterson wrote:
> Kris Kennaway wrote:
>> Joe Peterson wrote:
>>> I just tried (under FreeBSD 7.0-RC1) to mount an ext2fs volume - I've
>>> mounted it before with no trouble on this same FreeBSD version.  This
>>> time, mount appeared to hang.  I noticed that I can see the contents of
>>> the volume under the mount point, so the mount seemed to "work", but the
>>> process is stuff.  "ps" shows:
>>>
>>> root   1307  0.0  0.0  3156   792  p6  D+    5:21PM   0:00.00 mount
>>> /mnt/linux-home
>>>
>>> The "ps" man page says that "D" means: "Marks a process in disk (or
>>> other short term, uninterruptible) wait."
>>>
>>> Is there any way I can investigate what is going on?  I cannot umount
>>> (device busy) or break out of the mount command...
>> http://www.freebsd.org/doc/en_US.ISO8859-1/books/developers-handbook/kerneldebug.html
> 
> But unfortunately I do not have KDB and DDB compiled into the kernel.
> And, obviously, if I reboot, I will lose this opportunity.  I suspect
> this to be an intermittent thing.  Is there anything I can extract while
> the system is running that would be useful?
> 
> 	Thanks, Joe
> 
> 

You can run kgdb on /dev/mem to obtain the backtrace.

Kris