From owner-freebsd-questions Sun Oct 29 19:17:43 2000 Delivered-To: freebsd-questions@freebsd.org Received: from sharmas.dhs.org (c62443-a.frmt1.sfba.home.com [24.0.69.165]) by hub.freebsd.org (Postfix) with ESMTP id 3802437B479 for ; Sun, 29 Oct 2000 19:17:41 -0800 (PST) Received: (from adsharma@localhost) by sharmas.dhs.org (8.9.3/8.9.3) id TAA27619; Sun, 29 Oct 2000 19:15:44 -0800 Date: Sun, 29 Oct 2000 19:15:44 -0800 From: Arun Sharma To: cjclark@alum.mit.edu Cc: freebsd-questions@FreeBSD.ORG Subject: Re: softupdates and (avoiding) fsck Message-ID: <20001029191544.A27575@sharmas.dhs.org> References: <20001029183443.A27388@sharmas.dhs.org> <20001029190021.Z75251@149.211.6.64.reflexcom.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2i In-Reply-To: <20001029190021.Z75251@149.211.6.64.reflexcom.com>; from cjclark@reflexnet.net on Sun, Oct 29, 2000 at 07:00:21PM -0800 Sender: owner-freebsd-questions@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG On Sun, Oct 29, 2000 at 07:00:21PM -0800, Crist J . Clark wrote: > There is no way around fsck'ing when the system is brought down > hard. (Not absolutely true, but you dowanna mount an unclean FS.) > Soft updates does _NOT_ guarantee that you will come out of such a > nasty thing without damage. It does make it much less likely, > however. Carefully read, > > /usr/src/sys/ufs/ffs/README > > For more information on what soft updates really does. That file doesn't exist in -current anymore. But I found some other file, which pointed me to: http://www.mckusick.com/softdep/ which says: > By ensuring that the only inconsistencies are unclaimed blocks or > inodes, soft updates can eliminate the need to run a filesystem check > program after every system crash. Instead, the system is brought up > immediately. When it is convenient, a snapshot is taken and a background > task can be run on on that snapshot to reclaim any lost blocks and > inodes. The use of a snapshot allows normal filesystem activity to > continue concurrently. -Arun To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message