From owner-freebsd-fs Wed Oct 14 07:01:30 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id HAA26014 for freebsd-fs-outgoing; Wed, 14 Oct 1998 07:01:30 -0700 (PDT) (envelope-from owner-freebsd-fs@FreeBSD.ORG) Received: from magicnet.magicnet.net (magicnet.magicnet.net [204.96.116.9]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id HAA26007 for ; Wed, 14 Oct 1998 07:01:26 -0700 (PDT) (envelope-from bill@bilver.magicnet.net) Received: (from root@localhost) by magicnet.magicnet.net (8.8.6/8.8.8) with UUCP id KAA20978 for freebsd-fs@freebsd.org; Wed, 14 Oct 1998 10:00:05 -0400 (EDT) Received: (from bill@localhost) by bilver.magicnet.net (8.9.1/8.9.1) id JAA10202 for freebsd-fs@freebsd.org; Wed, 14 Oct 1998 09:48:52 -0400 (EDT) From: Bill Vermillion Message-Id: <199810141348.JAA10202@bilver.magicnet.net> Subject: Re: filesystem safety and SCSI disk write caching In-Reply-To: <199810140518.XAA15040@pluto.plutotech.com> from "Justin T. Gibbs" at "Oct 13, 98 11:11:41 pm" To: freebsd-fs@FreeBSD.ORG Date: Wed, 14 Oct 1998 09:48:52 -0400 (EDT) X-Mailer: ELM [version 2.4ME+ PL38 (25)] MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-freebsd-fs@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org Justin T. Gibbs recently said: > >> >It doesn't, since "# of anomalies == 0" with write caching > >> >disabled. > >> > >> This doesn't follow. If the cache is disabled, it doesn't > >> matter if the drive loses power due to hitting the reset > >> button. We already know that losing power on a drive that > >> cached data will not work. > >We do? > Of course we do. Why do you think my position on this subject has > always been, "Write caching is fine so long as you use a UPS"? There was at least one model of IBM's high-end SCSI drives which when power was lost, would use the inertia from the spinning platters to generate current from the motor, in order to flush the on-board drive cache. Anyone recall that model number? To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-fs" in the body of the message