From owner-freebsd-fs Fri Oct 2 12:30:33 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id MAA21755 for freebsd-fs-outgoing; Fri, 2 Oct 1998 12:30:33 -0700 (PDT) (envelope-from owner-freebsd-fs@FreeBSD.ORG) Received: from pluto.plutotech.com (mail.plutotech.com [206.168.67.137]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id MAA21737; Fri, 2 Oct 1998 12:30:21 -0700 (PDT) (envelope-from gibbs@plutotech.com) Received: from narnia.plutotech.com (narnia.plutotech.com [206.168.67.130]) by pluto.plutotech.com (8.8.7/8.8.5) with ESMTP id NAA11650; Fri, 2 Oct 1998 13:29:57 -0600 (MDT) Message-Id: <199810021929.NAA11650@pluto.plutotech.com> X-Mailer: exmh version 2.0.2 2/24/98 To: Wilko Bulte cc: Don.Lewis@tsc.tdk.com (Don Lewis), freebsd-fs@FreeBSD.ORG, freebsd-scsi@FreeBSD.ORG Subject: Re: filesystem safety and SCSI disk write caching In-reply-to: Your message of "Fri, 02 Oct 1998 14:06:50 +0200." <199810021206.OAA29167@yedi.iaf.nl> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Date: Fri, 02 Oct 1998 13:23:27 -0600 From: "Justin T. Gibbs" Sender: owner-freebsd-fs@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org >Yuck. Write caching on disks is evil. I've discussed this kind of >thing at great length with the disk gurus at work. There is consensus: >write caching is not to be trusted, there are even firmware incarnations >out there that get confused by a SCSI bus reset and loose track of what >they have cached. Admittedly this is junk firmware, but it seems to >happen. Your statement doesn't seem to be "write caching is inherently evil", but "there are many drives with bogus firmware where write caching is evil". There is a big difference. If you have a sane device and a UPS, write caching is not evil at all. -- Justin To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-fs" in the body of the message