From owner-freebsd-fs@FreeBSD.ORG Fri Aug 27 01:33:06 2010 Return-Path: Delivered-To: freebsd-fs@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id A65FD1065675 for ; Fri, 27 Aug 2010 01:33:06 +0000 (UTC) (envelope-from dougb@FreeBSD.org) Received: from mail2.fluidhosting.com (mx21.fluidhosting.com [204.14.89.4]) by mx1.freebsd.org (Postfix) with ESMTP id 537E38FC1F for ; Fri, 27 Aug 2010 01:33:06 +0000 (UTC) Received: (qmail 17247 invoked by uid 399); 27 Aug 2010 01:33:05 -0000 Received: from localhost (HELO ?192.168.0.142?) (dougb@dougbarton.us@127.0.0.1) by localhost with ESMTPAM; 27 Aug 2010 01:33:05 -0000 X-Originating-IP: 127.0.0.1 X-Sender: dougb@dougbarton.us Message-ID: <4C7715D0.10604@FreeBSD.org> Date: Thu, 26 Aug 2010 18:33:04 -0700 From: Doug Barton Organization: http://SupersetSolutions.com/ User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.2.8) Gecko/20100802 Thunderbird/3.1.2 MIME-Version: 1.0 To: freebsd-fs@freebsd.org X-Enigmail-Version: 1.2a1pre OpenPGP: id=1A1ABC84 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Subject: Difference of opinion about my disk geometry X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 27 Aug 2010 01:33:06 -0000 Howdy, What I've done for years in order to create a dual-boot between windows and FreeBSD, with one shared fat32 data partition; is to boot the FreeBSD install CD, create the 3 primary partitions, install FreeBSD, install Windows into the 1st primary partition, then boot the FreeBSD CD again and install the boot mgr. My rationale for this is that we (FreeBSD) know more about modern disk geometry than Windows XP does, and this method has always served me well. What I've done now is purchase a new HD for my laptop because the old one was starting to act dodgy. It's a 250 GB Hitachi Travelstar, SATA 300 in case anyone cares (which is the same as what was installed by Dell, except the old one was 100 GB). Since I have more space I'm attempting to experiment with more stuff as you may have seen from my other posts. However, FreeBSD disagrees with Windows and Linux about what the right geometry should look like. Depending on which OS I use to create partitions I get various errors about whether or not things end on cylinder and/or track boundaries. This does not seem like a good thing. Below are what the various OS' think about the disk. (Ignore the fact that the 3rd partition has an unknown type, that used to be a FreeBSD partition that seems to have been mangled by grub2, which I'm going to fix later.) When I run FreeBSD fdisk from sysinstall I get the following message: It is safe to use 484521/16/63 as the disk geometry blah blah blah, Do you want to change this? I've been saying no, but now I think what I want to do is say yes, and change it to 30401/255/63 which is what Windows and Linux think it is, and repartition the whole drive. Does that sound reasonable? Of course this prompts me to ask the questions of why are we looking at this differently than Windows and Linux, and what are the advantages/disadvantages to the 2 methods? Thanks again, Doug Windows: Sectors/Track 63 Size 232.88 GB (250,056,737,280 bytes) Total Cylinders 30,401 Total Sectors 488,392,065 Tracks/Cylinder 255 Linux: fdisk -l Disk /dev/sda: 250.1 GB, 250059350016 bytes 255 heads, 63 sectors/track, 30401 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Device Boot Start End Blocks Id System /dev/sda1 1 3264 26214016+ 7 HPFS/NTFS Partition 1 does not end on cylinder boundary. /dev/sda2 3264 18276 120587585+ f W95 Ext'd (LBA) /dev/sda3 * 18277 27414 73400166 b5 Unknown Partition 3 does not end on cylinder boundary. /dev/sda4 27414 30402 23996448 a5 FreeBSD Partition 4 does not end on cylinder boundary. /dev/sda5 3264 16318 104860255+ 6 FAT16 /dev/sda6 16319 16971 5242880 83 Linux /dev/sda7 16971 17232 2096128 82 Linux swap / Solaris /dev/sda8 17233 17493 2096128 83 Linux /dev/sda9 17494 18276 6288384 83 Linux fdisk -c -l Device Boot Start End Blocks Id System /dev/sda1 1 3264 26214016+ 7 HPFS/NTFS /dev/sda2 3264 18276 120587585+ f W95 Ext'd (LBA) /dev/sda3 * 18277 27414 73400166 b5 Unknown /dev/sda4 27414 30402 23996448 a5 FreeBSD /dev/sda5 3264 16318 104860255+ 6 FAT16 /dev/sda6 16319 16971 5242880 83 Linux /dev/sda7 16971 17232 2096128 82 Linux swap / Solaris /dev/sda8 17233 17493 2096128 83 Linux /dev/sda9 17494 18276 6288384 83 Linux FreeBSD: ******* Working on device /dev/ad0 ******* parameters extracted from in-core disklabel are: cylinders=484521 heads=16 sectors/track=63 (1008 blks/cyl) Figures below won't work with BIOS for partitions not in cyl 1 parameters to be used for BIOS calculations are: cylinders=484521 heads=16 sectors/track=63 (1008 blks/cyl) Media sector size is 512 Warning: BIOS sector numbering starts with sector 1 Information from DOS bootblock is: The data for partition 1 is: sysid 7 (0x07),(OS/2 HPFS, NTFS, QNX-2 (16 bit) or Advanced UNIX) start 63, size 52428033 (25599 Meg), flag 0 beg: cyl 0/ head 1/ sector 1; end: cyl 1023/ head 15/ sector 63 The data for partition 2 is: sysid 15 (0x0f),(Extended DOS (LBA)) start 52428157, size 241175171 (117761 Meg), flag 0 beg: cyl 1023/ head 254/ sector 63; end: cyl 1023/ head 254/ sector 63 The data for partition 3 is: sysid 181 (0xb5),(unknown) start 293603940, size 146800332 (71679 Meg), flag 80 (active) beg: cyl 1023/ head 255/ sector 63; end: cyl 1023/ head 15/ sector 63 The data for partition 4 is: sysid 165 (0xa5),(FreeBSD/NetBSD/386BSD) start 440404272, size 47992896 (23434 Meg), flag 0 beg: cyl 1023/ head 255/ sector 63; end: cyl 1023/ head 15/ sector 63