From owner-freebsd-current@FreeBSD.ORG Wed Mar 25 21:51:30 2009 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id A22BB106564A for ; Wed, 25 Mar 2009 21:51:30 +0000 (UTC) (envelope-from pieter@degoeje.nl) Received: from smtp.utwente.nl (smtp2.utsp.utwente.nl [130.89.2.9]) by mx1.freebsd.org (Postfix) with ESMTP id 250EB8FC0C for ; Wed, 25 Mar 2009 21:51:29 +0000 (UTC) (envelope-from pieter@degoeje.nl) Received: from nox.student.utwente.nl (nox.student.utwente.nl [130.89.165.91]) by smtp.utwente.nl (8.12.10/SuSE Linux 0.7) with ESMTP id n2PLpMNG013556; Wed, 25 Mar 2009 22:51:22 +0100 From: Pieter de Goeje To: freebsd-current@freebsd.org Date: Wed, 25 Mar 2009 22:51:22 +0100 User-Agent: KMail/1.9.10 References: <20090320102824.W75873@rust.salford.ac.uk> <20090325203558.GA4533@wep4035.physik.uni-wuerzburg.de> <49CA9823.9050605@googlemail.com> In-Reply-To: <49CA9823.9050605@googlemail.com> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200903252251.22791.pieter@degoeje.nl> X-UTwente-MailScanner-Information: Scanned by MailScanner. Contact servicedesk@icts.utwente.nl for more information. X-UTwente-MailScanner: Found to be clean X-UTwente-MailScanner-From: pieter@degoeje.nl X-Spam-Status: No Cc: "army.of.root" Subject: Re: Apparently spurious ZFS CRC errors (was Re: ZFS data error without reasons) X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 25 Mar 2009 21:51:30 -0000 On Wednesday 25 March 2009 21:46:27 army.of.root wrote: > Alexey Shuvaev wrote: > > On Wed, Mar 25, 2009 at 07:38:32PM +0100, Bernd Walter wrote: > >> On Wed, Mar 25, 2009 at 06:04:08PM +0000, Mark Powell wrote: > >>> On Wed, 25 Mar 2009, Bernd Walter wrote: > >>>> On Wed, Mar 25, 2009 at 03:21:28PM +0100, Alexander Leidinger wrote: > >>>> I wouldn't be surprised if the problem is in the drive firmware. > >>>> Preread and wc both have the potential to put a lot load to the drives > >>>> and can trigger bugs that otherwise wouldn't matter. > >>> > >>> I've emailed WD support for more info. Not expecting much though. > >>> From reading other threads on these Green Power drives them seem rather > >>> crap. This is my model and firmware: > >>> > >>> http://www.datacent.com/datarecovery/hdd/western_digital/WD10EADS-00L5B > >>>1 > >>> > >>> There's some head park problem too, but with 5s ZFS sync I don't think > >>> it applies in this case: > >>> > >>> http://www.silentpcreview.com/forums/viewtopic.php?t=51401&postdays=0&p > >>>ostorder=asc&start=120&sid=a1caf68d80ef8fecc5d9e86defde4c19 > >>> http://kerneltrap.org/mailarchive/linux-kernel/2008/4/9/1386304 > >>> > >>>> I also have a system running WD drives and ECC RAM which show CRC > >>>> errors > >>>> > >>> >from time to time, while all other systems have no CRC problem at all. > >>> > >>> Interesting. Are those CRC problems with WC on or off? > >> > >> WC is on, prefetch is off, but only because it had bad performance with > >> MySQL. > >> Drives are Serial ATA II > >> I don't know if it is with the drives, but other reasons are less > >> likely in my opinion. > >> The system is located in a data center and since I only get a few errors > >> I decided to live with it and not to debug it further. > > > > Hello! > > > > Me too... > > > > I don't use zfs, just ufs2 + soft updates, but I see sometimes rather > > heavy data corruption (most often on / filesystem). > > No kernel messages, I can shut down the system successfully just > > to find the remnants of filesystems on the next boot. > > It doesn't happen often, I think compiling ports in a jail + some > > activity in the host increase the probability of a failure. > > > > The drive is: > > ATA channel 3: > > Master: ad6 SATA revision 2.x > > > > hw.ata.wc=1 (default) > > > > FWIW, > > Alexey. > > Hi :) > > Damn f**k ! - I just bought WD harddrives for my Workstation... I find this all very odd because I have a pair of WDC WD6400AAKS-00A7B0 drives using UFS2 + SU on the latest -CURRENT (i386) and no corruption at all (as far as I can tell ofcourse). The drives are pretty fast btw. Just for fun I gstriped both of them and got speeds in excess of 200MB/sec. On another PC I've got a WDC WD10EACS-00ZJB0 1TB "Green Power" disk, also using UFS2+SU and no problems at all. That PC is running 7-STABLE however. > > is there any way to detect silent data corruption without ZFS ? Perhaps if you mirror a couple of drives you can manually verify that they have the same md5sum. > > best regards > > PS: Thanks for all your work, I'm looking soo forward to 8.0 I cant even > tell you how much :) Me too :-) -- Pieter de Goeje