From owner-freebsd-stable@FreeBSD.ORG Fri Nov 7 08:36:30 2008 Return-Path: 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 87606106567D for ; Fri, 7 Nov 2008 08:36:30 +0000 (UTC) (envelope-from jdc@koitsu.dyndns.org) Received: from QMTA01.emeryville.ca.mail.comcast.net (qmta01.emeryville.ca.mail.comcast.net [76.96.30.16]) by mx1.freebsd.org (Postfix) with ESMTP id 686CC8FC16 for ; Fri, 7 Nov 2008 08:36:30 +0000 (UTC) (envelope-from jdc@koitsu.dyndns.org) Received: from OMTA07.emeryville.ca.mail.comcast.net ([76.96.30.59]) by QMTA01.emeryville.ca.mail.comcast.net with comcast id c8Yp1a0021GXsucA18cWcv; Fri, 07 Nov 2008 08:36:30 +0000 Received: from koitsu.dyndns.org ([69.181.141.110]) by OMTA07.emeryville.ca.mail.comcast.net with comcast id c8cS1a0052P6wsM8T8cTnl; Fri, 07 Nov 2008 08:36:27 +0000 X-Authority-Analysis: v=1.0 c=1 a=NScBMle9X3IA:10 a=40FIlvht7DMA:10 a=tSd2Yfa9AAAA:8 a=8pif782wAAAA:8 a=hD80L64hAAAA:8 a=QycZ5dHgAAAA:8 a=RkybPS4Kh4YlctgQl98A:9 a=g_OC5pzheJzSf3dGS4gA:7 a=GErg-guPOWZ5_0QS_lz1ore1qZYA:4 a=EoioJ0NPDVgA:10 a=LY0hPdMaydYA:10 Received: by icarus.home.lan (Postfix, from userid 1000) id AA5765C34; Fri, 7 Nov 2008 00:36:26 -0800 (PST) Date: Fri, 7 Nov 2008 00:36:26 -0800 From: Jeremy Chadwick To: Artem Belevich Message-ID: <20081107083626.GA1583@icarus.home.lan> References: <20081107071752.GA5842@icarus.home.lan> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.18 (2008-05-17) Cc: votdev@gmx.de, freebsd-hardware@freebsd.org, freebsd-stable@freebsd.org, sos@freebsd.org Subject: Re: Western Digital hard disks and ATA timeouts X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 07 Nov 2008 08:36:30 -0000 On Fri, Nov 07, 2008 at 12:08:01AM -0800, Artem Belevich wrote: > > Note that Western Digital's "RAID edition" drives claim to take up to 7 > > seconds to reallocate sectors, using something they call TLER, which > > force-limits the amount of time the drive can spend reallocating. TLER > > cannot be disabled: > > TLER can be enabled/disabled on recent WD drives (SE16/RE2/GP). SE16/GP > come with TLER off, RE2 with TLER on. Google WDTLER utility. > It can apparently be obtained from WD by asking them nicely. > Or, yet again, google is your friend. Here's one example - > http://www.hardforum.com/archive/index.php/t-1191548.html Thanks for the information. Nice to know one of their FAQ entries is false. Also, note that "SE16/RE2/GP" is not specific enough; I have SE16 drives from 2005, and I highly doubt those have TLER capability due to their age. Also, there's a Wikipedia article on this whole fiasco. http://en.wikipedia.org/wiki/Time-Limited_Error_Recovery It also appears Samsung drives have a similar feature called CCTL, which uses a value of 7 or 8 seconds: http://www.samsung.com/global/business/hdd/learningresource/whitepapers/LearningResource_CCTL.html But regardless of TLER being toggleable, FreeBSD's ATA command timeout of 5 seconds is too aggressive, and should be increased. Likewise, the value should be a sysctl, so those who do want such aggressive values can use it at the community's -- or their own -- behest. -- | Jeremy Chadwick jdc at parodius.com | | Parodius Networking http://www.parodius.com/ | | UNIX Systems Administrator Mountain View, CA, USA | | Making life hard for others since 1977. PGP: 4BD6C0CB |