From owner-freebsd-fs@FreeBSD.ORG  Sat Feb  9 04:22:09 2008
Return-Path: <owner-freebsd-fs@FreeBSD.ORG>
Delivered-To: freebsd-fs@freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34])
	by hub.freebsd.org (Postfix) with ESMTP id 5017E16A418
	for <freebsd-fs@freebsd.org>; Sat,  9 Feb 2008 04:22:09 +0000 (UTC)
	(envelope-from julian@elischer.org)
Received: from outU.internet-mail-service.net (outU.internet-mail-service.net
	[216.240.47.244])
	by mx1.freebsd.org (Postfix) with ESMTP id 3A03F13C457
	for <freebsd-fs@freebsd.org>; Sat,  9 Feb 2008 04:22:09 +0000 (UTC)
	(envelope-from julian@elischer.org)
Received: from mx0.idiom.com (HELO idiom.com) (216.240.32.160)
	by out.internet-mail-service.net (qpsmtpd/0.40) with ESMTP;
	Fri, 08 Feb 2008 20:22:08 -0800
Received: from julian-mac.elischer.org (localhost [127.0.0.1])
	by idiom.com (Postfix) with ESMTP id B145A12714B;
	Fri,  8 Feb 2008 20:22:07 -0800 (PST)
Message-ID: <47AD2A75.8010908@elischer.org>
Date: Fri, 08 Feb 2008 20:22:13 -0800
From: Julian Elischer <julian@elischer.org>
User-Agent: Thunderbird 2.0.0.9 (Macintosh/20071031)
MIME-Version: 1.0
To: Joe Peterson <joe@skyrush.com>
References: <47ACD7D4.5050905@skyrush.com>	<D6B0BBFB-D6DB-4DE1-9094-8EA69710A10C@apple.com>	<47ACDE82.1050100@skyrush.com>	<20080208173517.rdtobnxqg4g004c4@www.wolves.k12.mo.us>
	<47ACF0AE.3040802@skyrush.com> <47ACF338.3020802@elischer.org>
	<47AD1979.8020704@skyrush.com>
In-Reply-To: <47AD1979.8020704@skyrush.com>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit
Cc: freebsd-fs@freebsd.org, freebsd-stable@freebsd.org
Subject: Re: Analysis of disk file block with ZFS checksum error
X-BeenThere: freebsd-fs@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: Filesystems <freebsd-fs.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-fs>,
	<mailto:freebsd-fs-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-fs>
List-Post: <mailto:freebsd-fs@freebsd.org>
List-Help: <mailto:freebsd-fs-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-fs>,
	<mailto:freebsd-fs-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Sat, 09 Feb 2008 04:22:09 -0000

Joe Peterson wrote:
> Julian Elischer wrote:
>> it could be an old file..
>> what kind of disks?
> 
> It's a Seagate ST3500630A parallel ATA drive.
> 
>> I had a scenario where 3ware controllers were just failing to write to
>> a drive in the array, so old data showed through.
> 
> I have an Intel ICH4 controller - nothing unusual.
> 
>> the filesystem and the partitions and the raids all were on different
>> alignments so teh only part of the system that had a boundary that 
>> aligned with the bad data was the physical stripes laid down by the 
>> controller.  It was 64k stripes and 64k data missing, exactly on
>> stripe boundaries. Due to the fact that FreeBSD had partitioned the 
>> drive staring at 63 blocks in, nothing else aligned with the problem.
> 
> Hmm, well this is a straight-forward disk situation - never used RAID on
> this drive.  Give what is happening, I wonder the changes of it being
> HW, OS, or a filesystem issue.
> 
> 					-Joe

still, see whether the 64k lines up with the drive or with
the filesystem (if the filesystem is not on an exact 64k boundary
of the drive).