From owner-freebsd-fs@FreeBSD.ORG Fri Dec 7 18:21:05 2012 Return-Path: Delivered-To: freebsd-fs@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id C69D648D for ; Fri, 7 Dec 2012 18:21:05 +0000 (UTC) (envelope-from yanegomi@gmail.com) Received: from mail-pb0-f54.google.com (mail-pb0-f54.google.com [209.85.160.54]) by mx1.freebsd.org (Postfix) with ESMTP id 8FF7B8FC14 for ; Fri, 7 Dec 2012 18:21:05 +0000 (UTC) Received: by mail-pb0-f54.google.com with SMTP id wz12so562847pbc.13 for ; Fri, 07 Dec 2012 10:21:05 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=references:mime-version:in-reply-to:content-type :content-transfer-encoding:message-id:cc:x-mailer:from:subject:date :to; bh=Q2iEN0/v663AP3BCIlHmsE94qkpU2vJBR2oN3ihSHEA=; b=BN9ku0y+0GAwTtcFEldA7BzjgY/Wja8pI+NTweEAf5NmDLJmUspabf/xaHHZFvVotU TSlwvg6+Tt/P0kuEf5DqtIAEhUNDqixHW2aMxPoz7xO8rO6e6ZJpqt0IknectFHQlRcF hfmYPTg9YYcbHjOIhvhGb9f6sSrL1LGT3JZOw9AlKQ7QS+Qe/DCRexp1xG33nBk75X0D If1hac4VayjHAdOzax1D204Jrw5GMPKhxmsKvnrpWeqmbLTXvwHhNXWC4N0+uuW3xs6q cUQ6/fMbfbfN5Al37GhG3VMstJ2btJ0M01fEtIrsV8koqByRySZJsYrdv06ilLx9ZUpC rhtw== Received: by 10.68.204.103 with SMTP id kx7mr18203083pbc.33.1354904465101; Fri, 07 Dec 2012 10:21:05 -0800 (PST) Received: from [192.168.20.12] (c-24-19-191-56.hsd1.wa.comcast.net. [24.19.191.56]) by mx.google.com with ESMTPS id zv10sm7051614pbc.76.2012.12.07.10.21.02 (version=SSLv3 cipher=OTHER); Fri, 07 Dec 2012 10:21:03 -0800 (PST) References: <50C1CB34.3000308@icritical.com> <50C1DDE8.9030503@icritical.com> <20121207172240.037306e1@fabiankeil.de> Mime-Version: 1.0 (1.0) In-Reply-To: <20121207172240.037306e1@fabiankeil.de> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: quoted-printable Message-Id: <79E03100-A019-4579-8762-50FBB82DD356@gmail.com> X-Mailer: iPhone Mail (10A523) From: Garrett Cooper Subject: Re: ZFS hang Date: Fri, 7 Dec 2012 10:21:01 -0800 To: Fabian Keil Cc: "freebsd-fs@freebsd.org" X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 07 Dec 2012 18:21:05 -0000 On Dec 7, 2012, at 8:22 AM, Fabian Keil wrote= : > Matt Burke wrote: >=20 >> Obviously, the cause of my problems would seem to be a hosed disk. Howeve= r >> the kernel msgbuf shows no complaints from the drive before reboot. >>=20 >> da8 is a 60GB OCZ Agility 3 SSD (purchased prior to realising just how >> unreliable they are). According to the SMART data, it's had just 146GB of= >> reads and 278GB writes over 3 power cycles with only 3 months power on >> time, similar to the others that have failed (~60% failure rate for ours)= >>=20 >> I can understand the drive failing, I just can't understand how it hung t= he >> system. I have had a similar thing happen on one of these machines before= >> (with GENERIC and no dumpdev, so no debugging) with one of these disks on= >> an Areca HBA. >=20 > In CURRENT, parts of the cam layer can silently hang under certain > circumstances and this can negatively affect various other subsystems > including ZFS: > http://lists.freebsd.org/pipermail/freebsd-current/2012-October/037413.htm= l >=20 > I suppose this regression is old enough to have trickled down > to the stable branches by now. >=20 > I'm not saying that this is definitively the problem you are > seeing, but I think it would explain the symptoms. >=20 >> Could there be a problem with ATA devices on SCSI controllers which is >> causing failures to be silently dropped? Is ZFS lacking a timeout on IO c= alls? >=20 > I believe ZFS is designed with the expectation that timeouts are > handled by the layers below it, so technically it doesn't "lack" > the timeouts for IO calls ... I've noticed hangs on reboot as well recently (in the last 2-3 months) with m= y ata single disk pools and my mfi pool. All storage disks seem healthy... T= he pools were running v28 with the zfs features upgrade. Thanks, -Garrett=