Subject: Re: i386 + cylinder boundaries
To: Garry Dolley <garry@linuxstart.com>
From: Manuel Bouyer <bouyer@antioche.lip6.fr>
List: tech-install
Date: 01/09/2000 17:38:17
On Sun, Jan 09, 2000 at 12:17:54AM -0800, Garry Dolley wrote:
> hi,
>
> I successfully installed and configured NetBSD 1.4 on my Pentium III
> 450Mhz w/ two IDE disks. I installed it on the first IDE disk which is
> 27 Gigs and put it in the 3rd primary partition. Everything went A-OK
> :) Trouble is, I've been reinstalling NetBSd to try to get it to end
> it's partition on a cylinder boundary so Partition Magic and Linux LILO
> won't complain. I'm not so concerned with Lilo, but Partition Magic
> won't even start it if detects a partition does not end on a cylinder
> boundary. SOO.. my question is, how should I go about calculating where
> I need to end my netbsd partition to achieve the results I want? Thanks
> for the help guys..
start 'fdisk -u wd0' under NetBSD
fdisk will print among other things the BIOS geometry, something like:
rochebonne#/>fdisk -u wd0
NetBSD disklabel disk geometry:
cylinders: 16383 heads: 16 sectors/track: 63 (1008 sectors/cylinder)
BIOS disk geometry:
cylinders: 1023 heads: 255 sectors/track: 63 (16065 sectors/cylinder)
then anserw 'no' until you get to the NetBSD partition, at wich point you need
to anserw 'y'.
Don't change 'start' but lower 'size' so that 'start+size' is a multiple
of "BIOS sectors/cylinder" (16065 in my exemple). When it asks
"Explicitly specify beg/end address" anserw 'n'.
Then keep anserwing 'n' untill it asks "Should we write new partition table".
Note: it's safe to lower size because NetBSD doesn't uses the size of it's
bios partition, it relies on what's in its disklabel instead.
--
Manuel Bouyer <bouyer@antioche.eu.org>
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