From owner-freebsd-questions@FreeBSD.ORG Thu Dec 23 06:37:29 2004 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 32D4616A4CE for ; Thu, 23 Dec 2004 06:37:29 +0000 (GMT) Received: from green.rahul.net (green.rahul.net [192.160.13.49]) by mx1.FreeBSD.org (Postfix) with ESMTP id DD67743D53 for ; Thu, 23 Dec 2004 06:37:28 +0000 (GMT) (envelope-from conover@rahul.net) Received: from green.rahul.net (localhost.localdomain [127.0.0.1]) by green.rahul.net (Postfix) with SMTP id 19555BE8BE for ; Wed, 22 Dec 2004 22:37:26 -0800 (PST) Received: (qmail 17930 invoked by uid 4199); 23 Dec 2004 06:36:03 -0000 Date: 23 Dec 2004 06:36:03 -0000 Message-ID: <20041223063603.17929.qmail@rahul.net> To: Damien Hull In-Reply-To: <1103781420.16972.17.camel@tower1.digitaloverload.local> References: <20041221104508.1002.qmail@rahul.net> <41C8DC87.5080207@mac.com> <1103781420.16972.17.camel@tower1.digitaloverload.local> From: conover@rahul.net (John Conover) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit cc: freebsd-questions Subject: Re: UFS2 with Soft Updates Robust? X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list Reply-To: John Conover List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 23 Dec 2004 06:37:29 -0000 Damien Hull writes: > On Tue, 2004-12-21 at 21:31 -0500, Chuck Swiger wrote: > > John Conover wrote: > > > Is UFS2 with soft updates the most robust file system in freebsd? > > > > No, although UFS2 with softupdates is robust enough for production use. > > > > If you make the filesystem writes syncronous and disable write caching on the > > hard drive, you will improve the robustness at significant cost to performance. > > > > Are you saying that the UFS2 file system sucks? If so what options does > one have? > > I've read that softupdates should be turned on. How much of a > performance loss will I see if I turn softupates off? > Oh, no, not at all, Damien-I consider UFS/FFS quite sturdy. I put it in a PC with softupdates on, (and no other options, like cache write through, synchronous writes, etc.,) and for 30 minutes cycled the machine's power switch 15 times, hitting the power as soon as fsck started, etc. to see if I could induce an exception/fault scenario with something it couldn't fix auto'magically. Also, I hit the power switch with a dozen cat /dev/zero > bigfile1, ..., processes, too-after they had filled up about 20G of spinning real estate. UFS/FFS withstood the abuse well. So I have been told, for maximum reliability/durability, cache write through should be enabled, along with synchronous writes-albeit at a substantial speed penalty, (I don't know how much-that's a test for another day.) So far, I've done this on about a half dozen open source OS distributions, and one Sys V Rel. 4 with Veritas journaling FS. FreeBSD and Veritas are the only two that survived. John For the record, the box is an Intel reference MB, and an Adaptec 2940UW, with a Fujitsu 35G SCSI drive. All out of the box default settings. No RAID. -- John Conover, conover@rahul.net, http://www.johncon.com/