From owner-freebsd-geom@FreeBSD.ORG Tue Apr 10 17:55:23 2007 Return-Path: X-Original-To: freebsd-geom@freebsd.org Delivered-To: freebsd-geom@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id 476C516A409 for ; Tue, 10 Apr 2007 17:55:23 +0000 (UTC) (envelope-from anderson@freebsd.org) Received: from mh1.centtech.com (moat3.centtech.com [64.129.166.50]) by mx1.freebsd.org (Postfix) with ESMTP id 17F1013C4BC for ; Tue, 10 Apr 2007 17:55:23 +0000 (UTC) (envelope-from anderson@freebsd.org) Received: from [10.177.171.220] (neutrino.centtech.com [10.177.171.220]) by mh1.centtech.com (8.13.8/8.13.8) with ESMTP id l3AHtMSE036108; Tue, 10 Apr 2007 12:55:22 -0500 (CDT) (envelope-from anderson@freebsd.org) Message-ID: <461BCF8A.3030307@freebsd.org> Date: Tue, 10 Apr 2007 12:55:22 -0500 From: Eric Anderson User-Agent: Thunderbird 1.5.0.10 (X11/20070320) MIME-Version: 1.0 To: Gergely CZUCZY References: <461A5EC6.8010000@freebsd.org> <20070409154407.GA88621@harmless.hu> <20070410111957.GA85578@garage.freebsd.pl> <461B75B2.40201@fer.hr> <20070410114115.GB85578@garage.freebsd.pl> <20070410161445.GA18858@keira.kiwi-computer.com> <20070410162129.GI85578@garage.freebsd.pl> <20070410172604.GA21036@keira.kiwi-computer.com> <461BCC85.2080900@freebsd.org> <20070410174607.GA26432@harmless.hu> In-Reply-To: <20070410174607.GA26432@harmless.hu> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Virus-Scanned: ClamAV 0.88.4/3064/Tue Apr 10 11:25:23 2007 on mh1.centtech.com X-Virus-Status: Clean X-Spam-Status: No, score=-2.6 required=8.0 tests=AWL,BAYES_00 autolearn=ham version=3.1.6 X-Spam-Checker-Version: SpamAssassin 3.1.6 (2006-10-03) on mh1.centtech.com Cc: freebsd-geom@freebsd.org Subject: Re: volume management X-BeenThere: freebsd-geom@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: GEOM-specific discussions and implementations List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 10 Apr 2007 17:55:23 -0000 On 04/10/07 12:46, Gergely CZUCZY wrote: > On Tue, Apr 10, 2007 at 12:42:29PM -0500, Eric Anderson wrote: >>>> It will be >>>> great to just fix everything in the kernel to handle errors properly, >>>> but good luck with that. >>> That's a worthy goal and something we should be pursuing. After all, >>> FreeBSD used to be noted for its stability. I wouldn't call panics a sign >>> of stability.. You're better off invalidating all the geom consumers and >>> leaving the rest of the system up so an admin can try to recover critical >>> data, or so the remaining geom providers can continue to function. >> There's been talk in the past about making the mount read-only instead of a panic in some >> situations, but I know nothing more than that. > I quite like this idea, but what about updates? I don't know > whether updates require additional space for UFS2 or not, but > I can imagine the opportunity when updates can be done while > there is no more space for allocating new blocks. I think the only time this might even be an option is under very minimal conditions. As Pawel said, if your FS is corrupt, you'll get hosed down the line. Personally, what I would want to prevent, is having a server go down due to one file system having an issue, when it is serving (or using) many more file systems. I currently have a box with 5 10Tb file systems on it, and when I mount a 6th file system (2Tb) which I *know* has metadata inconsistencies that fsck can't fix, I don't want it to take down all 50Tb of good solid storage. What I want is a blast to my logs, the erroneous file system to be evicted from further damage (mount read-only and marked as dirty) and trickle an i/o error to any processes trying to write to it. Even unmounting it would be ok, but that gets nasty with NFS servers and other things. Eric