From owner-freebsd-stable@FreeBSD.ORG  Thu Nov  3 20:28:12 2005
Return-Path: <owner-freebsd-stable@FreeBSD.ORG>
X-Original-To: freebsd-stable@freebsd.org
Delivered-To: freebsd-stable@freebsd.org
Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125])
	by hub.freebsd.org (Postfix) with ESMTP id 140D016A41F
	for <freebsd-stable@freebsd.org>; Thu,  3 Nov 2005 20:28:12 +0000 (GMT)
	(envelope-from jcr@canuck.co.uk)
Received: from aisdirect.co.uk (dsl-217-155-102-238.zen.co.uk
	[217.155.102.238])
	by mx1.FreeBSD.org (Postfix) with ESMTP id 57F5143D45
	for <freebsd-stable@freebsd.org>; Thu,  3 Nov 2005 20:28:11 +0000 (GMT)
	(envelope-from jcr@canuck.co.uk)
Received: from zuul ([192.168.0.220])
	by aisdirect.co.uk with esmtp (Exim 4.24; FreeBSD 4.8)
	id 1EXlga-000G0J-IL
	for freebsd-stable@freebsd.org; Thu, 03 Nov 2005 20:27:48 +0000
Message-ID: <436A7327.6080901@canuck.co.uk>
Date: Thu, 03 Nov 2005 20:29:27 +0000
From: jcr <jcr@canuck.co.uk>
User-Agent: Debian Thunderbird 1.0 (X11/20050116)
X-Accept-Language: en-us, en
MIME-Version: 1.0
To: freebsd-stable@freebsd.org
References: <436A6904.6050207@math.missouri.edu>
In-Reply-To: <436A6904.6050207@math.missouri.edu>
Content-Type: text/plain; charset=us-ascii; format=flowed
Content-Transfer-Encoding: 7bit
Subject: Re: DMA errors
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: Thu, 03 Nov 2005 20:28:12 -0000

Stephen Montgomery-Smith wrote:

> I found these messages on my computer, which is running a very recent 
> RELENG_5. Is this bad? Does it indicate that the disk is failing?
>
> Nov 3 07:35:48 cauchy kernel: ad4: FAILURE - READ_DMA
> status=51<READY,DSC,ERROR> error=40<UNCORRECTABLE> LBA=145908831
> Nov 3 07:35:51 cauchy kernel: ad4: FAILURE - READ_DMA
> status=51<READY,DSC,ERROR> error=40<UNCORRECTABLE> LBA=145908863
> Nov 3 07:35:55 cauchy kernel: ad4: FAILURE - READ_DMA
> status=51<READY,DSC,ERROR> error=40<UNCORRECTABLE> LBA=145908895
> Nov 3 07:35:59 cauchy kernel: ad4: FAILURE - READ_DMA
> status=51<READY,DSC,ERROR> error=40<UNCORRECTABLE> LBA=145908895
>
It could be a problem with the disk, the cable, or possibly software.

Try smartctl -a /dev/ad4 as root to find out if the errors were recorded 
by the drive.

Now is a good time to do a backup, just in case :)
-- 
</jcr>