From owner-freebsd-stable@FreeBSD.ORG Fri Nov 7 21:10:16 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 EC8F31065687 for ; Fri, 7 Nov 2008 21:10:15 +0000 (UTC) (envelope-from whizzter@gmail.com) Received: from ey-out-2122.google.com (ey-out-2122.google.com [74.125.78.25]) by mx1.freebsd.org (Postfix) with ESMTP id 726308FC21 for ; Fri, 7 Nov 2008 21:10:14 +0000 (UTC) (envelope-from whizzter@gmail.com) Received: by ey-out-2122.google.com with SMTP id 6so587996eyi.7 for ; Fri, 07 Nov 2008 13:10:13 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:message-id:date:from:to :subject:cc:in-reply-to:mime-version:content-type :content-transfer-encoding:content-disposition:references; bh=FiXBg7rLScyl3g9H1K05axgmOQ7VeDjdJIFKLTu+EwM=; b=vMopg2LW9XvwUem1jyejY+NWde96sn+9kMxwqo6KSETonjA1FvJ07lw1rARkTHvgJG +5I08kay5sX/bEhjZ1iv95FthXFgnczIjR5cXl6E5AK3voUD53EBfICSbL7p2MGx9/wa 9m2LQEkjYqN9LpejyN7/T8K/fN/UG+HHJnE8c= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:to:subject:cc:in-reply-to:mime-version :content-type:content-transfer-encoding:content-disposition :references; b=viBQfimEeItIhOZQGlB3jtwI6wB/UJ39WZbQcdowRmnwQgvM1ijEaTV+yDW8q3nYV8 yS1Gm4FDluZoDQ4qnc4TF0wKucfibltlla2uTkuutw5Ghybf/mE1ECocBKypEhT+4+Wn bJAprAVAFAGeyVoQnW8gWF8QxG3tYhYY4hTmQ= Received: by 10.103.46.12 with SMTP id y12mr2041734muj.136.1226090952837; Fri, 07 Nov 2008 12:49:12 -0800 (PST) Received: by 10.103.214.9 with HTTP; Fri, 7 Nov 2008 12:49:12 -0800 (PST) Message-ID: <436c7eda0811071249g33a81c75w85b971ad23a9847d@mail.gmail.com> Date: Fri, 7 Nov 2008 21:49:12 +0100 From: "Jonas Lund" To: "Peter Wemm" In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <20081107071752.GA5842@icarus.home.lan> Cc: Jeremy Chadwick , freebsd-hardware@freebsd.org, freebsd-stable@freebsd.org, votdev@gmx.de, 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 21:10:16 -0000 As i'm writing this i'm trying to rescue the contents of another computers disk. Something about the seek heads or something related to that is physically half-broken so the disk might need up to 10 retries just to read a sector, once read however it's usually no problem. I'm using myrescue (running on 6.2 so i don't know if it's included in the current ports but if anyone wants to run it on freebsd i've done the "gruntwork" for porting) so it's not a really big issue with all the timeouts as it'll try to read that sector again later, but had i had the sysctl i would've been a tad happier right now. As for the defaults being a small value i personally think it's better to throw out some messages/errors early on before the disk reaches a catastrophic state (Atleast on 6.2 the kernel will put out a message for each retry without giving faults, maybe more retries before throwing an error maybe?). By catastrpohic state i'm refering to that oh-so-famous google paper that did say that once a disk has started showing errors it doesn't have long to live, but i do trust that conclusion as i've been "warned" by these messages 2 times but ignored them until the disk went really bad. The main thing i'm trying to get through is that early warning and small problems are helluva lot better than big disasters. Thing of it like the oil meter on your car, it's not like you're gonna go out and drive 100s of km's in the wilderness if you know that the car is in a bad state. (Now if only smart info was reliable!) / Jonas 2008/11/7 Peter Wemm : > On Thu, Nov 6, 2008 at 11:17 PM, Jeremy Chadwick wrote: > [..] >> As stated, FreeBSD's ATA command timeout is hard-set to 5 seconds, and >> is not adjustable without editing the ATA code yourself and increasing >> the value. The FreeNAS folks have made patches available to turn the >> timeout value into a sysctl. >> >> Soren and/or others, please increase this timeout value. Five seconds >> has now been deemed too aggressive a default. And please consider >> migrating the timeout value into a sysctl. > > The 5 second timeout has been a problem for quite a while actually. > I've had a number of instances where I've had to increase it to 20 or > 30 seconds when recovering from marginal drives. The longest > "successful" recovery attempt I've seen was 26 seconds, I believe on a > Maxtor drive a few years ago. ("successful" == the drive spent 26 > seconds but eventually successfully read the sector). Even the IBM > death star drives could take much longer than 5 seconds to do a > recovery 5 years ago. 5 seconds has never been a good default. > > I think the timeout should be increased to at least 30 seconds. My > windows box has a timeout that goes for several minutes. > > If there is concern about FreeBSD appearing to hang, I could imagine > that a console warning message could be printed after 5 seconds. But > just say "drive has not yet responded". But give it more time. > > In this day and age we're generally not playing games with udma33 vs > 66, notched cables, poor CRC support etc. SATA seems to have > eliminated all that. Hmm, it might make sense to increase the timeout > on SATA connections to 2 or 3 minutes by default. > -- > Peter Wemm - peter@wemm.org; peter@FreeBSD.org; peter@yahoo-inc.com; KI6FJV > "All of this is for nothing if we don't go to the stars" - JMS/B5 > "If Java had true garbage collection, most programs would delete > themselves upon execution." -- Robert Sewell > _______________________________________________ > freebsd-hardware@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-hardware > To unsubscribe, send any mail to "freebsd-hardware-unsubscribe@freebsd.org" >