From owner-freebsd-stable@FreeBSD.ORG Tue Jul 1 22:15:30 2014 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 1632FC69; Tue, 1 Jul 2014 22:15:30 +0000 (UTC) Received: from nskntmtas02p.mx.bigpond.com (nskntmtas02p.mx.bigpond.com [61.9.168.140]) by mx1.freebsd.org (Postfix) with ESMTP id 806D324F5; Tue, 1 Jul 2014 22:15:28 +0000 (UTC) Received: from nskntcmgw05p ([61.9.169.165]) by nskntmtas02p.mx.bigpond.com with ESMTP id <20140701221527.UNGR2564.nskntmtas02p.mx.bigpond.com@nskntcmgw05p>; Tue, 1 Jul 2014 22:15:27 +0000 Received: from hermes.heuristicsystems.com.au ([121.210.107.100]) by nskntcmgw05p with BigPond Outbound id MAFS1o00j29zwdD01AFSSn; Tue, 01 Jul 2014 22:15:27 +0000 X-Authority-Analysis: v=2.0 cv=W5W6pGqk c=1 sm=1 a=SEJ2iDwVkb98DYvesvueMw==:17 a=JipEcVzqA9wA:10 a=oBnAVOPuztkA:10 a=IkcTkHD0fZMA:10 a=GHIR_BbyAAAA:8 a=6I5d2MoRAAAA:8 a=azj0dvhIOO4lg350HaIA:9 a=QEXdDO2ut3YA:10 a=SV7veod9ZcQA:10 a=SEJ2iDwVkb98DYvesvueMw==:117 Received: from [10.0.5.3] (ewsw01.hs [10.0.5.3]) (authenticated bits=0) by hermes.heuristicsystems.com.au (8.14.5/8.13.6) with ESMTP id s61MG2uc049113 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES128-SHA bits=128 verify=NOT); Wed, 2 Jul 2014 08:16:03 +1000 (EST) (envelope-from dewayne.geraghty@heuristicsystems.com.au) Message-ID: <53B332C6.6070007@heuristicsystems.com.au> Date: Wed, 02 Jul 2014 08:14:30 +1000 From: Dewayne Geraghty User-Agent: Mozilla/5.0 (Windows NT 6.1; rv:24.0) Gecko/20100101 Thunderbird/24.3.0 MIME-Version: 1.0 To: trasz@freebsd.org Subject: Re: 10/stable panic: softdep_deallocate_dependencies: dangling deps References: <021AFCAD-7B0B-47FB-AAFF-8F7085C7E1A6@gmail.com> <20140701184749.GA8617@brick.home> In-Reply-To: <20140701184749.GA8617@brick.home> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Cc: freebsd-stable@freebsd.org X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 01 Jul 2014 22:15:30 -0000 On 2/07/2014 4:47 AM, Edward Tomasz Napierała wrote: > Soft updates cannot gracefully handle IO errors. It _will_ panic. > You can either prevent errors from happening by using redundancy > (ie. mirroring), or disable soft updates. That's how it works, > sorry. > > In theory it would be possible to prevent this from happening; > panic here is actually to terminate the system before it corrupts > data, and in situations like this one, where the disk is no longer > accessible, it's not possible to corrupt anything. IIRC I've > actually added a workaround for that a while ago, but, as you can > see, it's not enough, and I don't understand soft updates well > enough to fix it properly. > > _______________________________________________ > freebsd-stable@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-stable > To unsubscribe, send any mail to "freebsd-stable-unsubscribe@freebsd.org" Thank-you for clarifying what we should expect with io failure. FreeBSD has been so reliable I'm sure that many (self included) have forgotten that this is the last "safe" option. Kind regards, Dewayne