From owner-freebsd-current@FreeBSD.ORG Mon Jul 26 22:35:06 2004 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 7EE5F16A4CE; Mon, 26 Jul 2004 22:35:06 +0000 (GMT) Received: from mail.dt.e-technik.uni-dortmund.de (mail.dt.e-technik.Uni-Dortmund.DE [129.217.163.1]) by mx1.FreeBSD.org (Postfix) with ESMTP id 32E7143D54; Mon, 26 Jul 2004 22:35:06 +0000 (GMT) (envelope-from ma@dt.e-technik.uni-dortmund.de) Received: from m2a2.dyndns.org (p5487CB64.dip.t-dialin.net [84.135.203.100]) E9DC9367F6; Tue, 27 Jul 2004 00:35:04 +0200 (CEST) Received: from localhost (localhost [127.0.0.1]) by merlin.emma.line.org (Postfix) with ESMTP id 32DD9B9EAA; Tue, 27 Jul 2004 00:35:03 +0200 (CEST) Received: from merlin.emma.line.org ([127.0.0.1]) by localhost (m2a2.dyndns.org [127.0.0.1]) (amavisd-new, port 10024) with LMTP id 28425-04; Tue, 27 Jul 2004 00:34:56 +0200 (CEST) Received: by merlin.emma.line.org (Postfix, from userid 500) id 9BBD2B9925; Tue, 27 Jul 2004 00:34:55 +0200 (CEST) To: Scott Long In-Reply-To: <20040726114142.E32601@pooker.samsco.org> (Scott Long's message of "Mon, 26 Jul 2004 11:49:55 -0600 (MDT)") References: <1090718450.2020.4.camel@illusion.com> <200407251112.46183.doconnor@gsoft.com.au> <20040726152151.GC1473@green.homeunix.org> <20040726114142.E32601@pooker.samsco.org> From: Matthias Andree Date: Tue, 27 Jul 2004 00:34:55 +0200 Message-ID: User-Agent: Gnus/5.110003 (No Gnus v0.3) Emacs/21.3 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Virus-Scanned: by amavisd-new at m2a2.dyndns.org cc: current@freebsd.org cc: bugghy Subject: Re: magic sysrq keys functionality X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 26 Jul 2004 22:35:06 -0000 Scott Long writes: > On Mon, 26 Jul 2004, Brian Fundakowski Feldman wrote: >> SoftUpdates guarantess that your file systems will not get corrupt. > This isn't entirely correct. Softupdates guarantees that you won't get > corruption due to metadata pointing to invalid or stale data blocks. > That's not the same as guaranteeing that there won't be any corruption. > Write caching on the drive combined with an in-opportune power loss or > other failure can easily leave you with corrupt or incomplete metadata > and/or data blocks. I've had a SCS HDD lock up (1997 Micropolis 4345WS showing its age and bad interaction with an Adaptec 2940UW Pro[*]) while softdep was writing to the drive and suffered *SEVERE* file system corruption, which tore down my /var/db/pkg and other stuff. [*] The same adaptor used to lock up every other week in a different hardware environment. I haven't seen this kind of trouble with the Tekram DC-390U I used to use, but I was too lazy to replace the Tekram until now. -- Matthias Andree Encrypted mail welcome: my GnuPG key ID is 0x052E7D95 (PGP/MIME preferred)