Subject: big IDE disks
To: None <>
From: Gordon W. Ross <>
List: current-users
Date: 12/28/1994 11:21:21
> Date: Wed, 28 Dec 1994 13:52:22 +1100
> From: Matthew Barry <>
> Is it possible to use an IDE disk of 1G with NetBSD? I have tried to
> partition my disk to be shared between NetBSD and DOS, but I am having no
> luck at all. Pfdisk.exe will write out a partition table with a
> geometry of 524 c, 64 h and 63 s, but not with 2100 c, 16 h and
> 63s. However, when the install for netbsd 1.0 tries to write the
> partition, it gets geometry failures from wd0. Needless to say things
> do not work out well from that point.
> So am I failing to set things up correctly? Or am I wasting my time?
> Any help will be much appreciated.

The geometry you specify to pfdisk needs to match what the BIOS gives
to the first-stage boot program, otherwise the boot program will get
the wrong sectors when trying to load the second-stage boot program.

When you start pfdisk and give the "L" command (list) it will show
you what the BIOS told it the geometry is (should be fine).  I made
it possible to override the geometry mostly so I could do testing
with a plain file instead of the master boot record.  You should
not override the geometry unless you know your second-stage boot
program will be able to deal with the somewhat messy result.

I suggest you just partition the 524 cylinders the BIOS thinks are
available into something convenient for you:
(i.e. type this at pfdisk)

	1    6   0   127  MS-DOS
	4 0xA5 128   523  NetBSD
	a 4

By the way, the pfdisk that most people got from
was an incomplete version, missing the documentation, boot files,
and sources for other systems.  The FreeBSD folks said they would
fix it, but for now you can get the whole package from:

	cd /pub
	get pfdisk-1.3.tar.gz

Lastly, I wrote pfdisk a very long time ago, and I don't really
use DOS much these days, so please forgive my lack of current
expertise on using pfdisk to make DOS live with *BSD...

Gordon W. Ross			  Internet: <>
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