From owner-freebsd-questions@FreeBSD.ORG Thu Dec 4 16:37:33 2003 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 C2F8116A4CE for ; Thu, 4 Dec 2003 16:37:33 -0800 (PST) Received: from smtp.covadmail.net (mx05.covadmail.net [63.65.120.65]) by mx1.FreeBSD.org (Postfix) with SMTP id 9B46D43FDF for ; Thu, 4 Dec 2003 16:37:31 -0800 (PST) (envelope-from strick@covad.net) Received: (covad.net 17955 invoked from network); 5 Dec 2003 00:37:26 -0000 Received: from unknown (HELO mist.nodomain) (67.101.98.88) by sun-qmail08 with SMTP; 5 Dec 2003 00:37:25 -0000 Received: from mist.nodomain (localhost [127.0.0.1]) by mist.nodomain (8.12.9p2/8.12.9) with ESMTP id hB50bL0v010809; Thu, 4 Dec 2003 16:37:22 -0800 (PST) (envelope-from dan@mist.nodomain) Received: (from dan@localhost) by mist.nodomain (8.12.9p2/8.12.9/Submit) id hB50bLHf010808; Thu, 4 Dec 2003 16:37:21 -0800 (PST) (envelope-from dan) Date: Thu, 4 Dec 2003 16:37:21 -0800 (PST) From: Dan Strick Message-Id: <200312050037.hB50bLHf010808@mist.nodomain> To: xscd@xscd.com cc: questions@freebsd.org cc: dan@mist.nodomain Subject: Re: Phoenix BIOS, hard disk data loss X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 05 Dec 2003 00:37:33 -0000 On Thu, 4 Dec 2003, xscd@xscd.com wrote: >> > Some months ago, just after buying a Tyan Tiger s2466 MPX dual processor > motherboard and installing FreeBSD 5.0 on it, I experienced a lot of > data loss (lost files and directories, unrecoverable by fsck). I > thought the problem might be related to disk geometry (I'm fairly new > to FreeBSD and the sysinstall disk geometry warning concerned me). > > However, after a couple months I decided to change just one setting in > the Phoenix BIOS: Large Disk Access Mode > > There are two options for Large Disk Access Mode: "DOS" and "Other" > > The help text for this item says: "This option denotes that a hard drive > with more than 1024 cylinders, more than 16 heads and or more than 64 > tracks per sector is present. Choose OTHER when using OSes such as > UNIX." > > So, at first I had chosen "Other." However, after all the data loss, I > felt I had nothing (more) to lose so I changed it to DOS just to see if > it made a difference. Apparently it did. I have experienced no more > lost data (from hard disk corruption or problems) in the six or so > months since I made the change. >> The large disk option sounds like it affects the "translated" disk geometry used by BIOS to increase the amount of disk accessible to software that uses the BIOS for disk i/o (e.g. DOS). FreeBSD uses the BIOS disk i/o facilities only to read the disk when booting. It is highly unlikely that your file system corruption problems were related to the BIOS Large Disk Access Mode option unless you were also using a non-FreeBSD OS on the same disk and it inadvertently did disk writes through the BIOS to wrong disk locations. Dan Strick strick@covad.net