From owner-freebsd-questions Wed Jan 30 13:30:31 2002 Delivered-To: freebsd-questions@freebsd.org Received: from mail8.nc.rr.com (fe8.southeast.rr.com [24.93.67.55]) by hub.freebsd.org (Postfix) with ESMTP id 6953637B417 for ; Wed, 30 Jan 2002 13:30:28 -0800 (PST) Received: from i8k.babbleon.org ([66.57.85.154]) by mail8.nc.rr.com with Microsoft SMTPSVC(5.5.1877.687.68); Wed, 30 Jan 2002 14:15:25 -0500 Received: by i8k.babbleon.org (Postfix, from userid 111) id D84744078; Wed, 30 Jan 2002 14:14:02 -0500 (EST) Content-Type: text/plain; charset="iso-8859-1" From: Brian T.Schellenberger To: Doug Poland , Espen Tagestad Subject: Re: Softupdates ( why not to use on / fs ) Date: Wed, 30 Jan 2002 14:14:02 -0500 X-Mailer: KMail [version 1.3] Cc: questions@FreeBSD.ORG References: <3C593C4A@epostleser.online.no> <20020130124756.A15728@modula.no> <20020130095919.B26823@polands.org> In-Reply-To: <20020130095919.B26823@polands.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Message-Id: <20020130191402.D84744078@i8k.babbleon.org> Sender: owner-freebsd-questions@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG Better lesson to have learned: a. Turn off write caching. This should be off by default IMHO. The default sacrifices out-of-the-box safety for out-of-the box performance numbers vis-a-vis Linux. If this happened to you and you already had write caching off already, then *that* would be quite interesting, and both the members of hte list and the author of the softupdates code would probably want to know about it. Only a file which is just being written should be at risk from turning on soft updates without write caching. On Wednesday 30 January 2002 10:59 am, Doug Poland wrote: > On Wed, Jan 30, 2002 at 12:47:56PM +0100, Espen Tagestad wrote: > > On Wed, Jan 30, 2002 at 12:34:11PM +0100, Christer Gundersen wrote: > > > As i read the RELEASE NOTES, i see that SOFTUPDATES will be activated > > > by default under install. but it also says that it will not enable > > > SOFTUPDATES on the root ( / ) fs . why? is that bad? > > > > Because with SoftUpdates read/write operations often delay, sometimes > > up to 30 seconds before it's done. Then, if a machine crash occurs it > > may lead to a larger loss of data. That can cause unrecoverable damage > > to your system. > > I can attest to that. Last week I changed my /etc/fstab. Immediatley > after exiting vi, I mounted a floppy with a FAT filesystem with the > intention of saving this important system file. I forgot to disable > the write-protect tab on the floppy and simply popped the floppy out > of the drive, switched the tab, and put it back in. When I did an > ls /dev/fd0 my system hung. I reset the machine, the / partition > had errors that fsck fixed. Unfortunately, /etc/fstab was gone. Ouch. > It took me two hours to get my box up and running again. > > Lessons learned: > 1. turn off softupdates on / > 2. be VERY careful mounting/unmounting removable media > 3. before disaster strikes... > 4. have a fixit floppy/cd before #3 > 5. print portion of handbook dealing with Emergency Restore Procedures > > HTH, -- Brian T. Schellenberger . . . . . . . bts@wnt.sas.com (work) Brian, the man from Babble-On . . . . bts@babbleon.org (personal) ME --> http://www.babbleon.org http://www.eff.org <-- GOOD GUYS --> http://www.programming-freedom.org To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message