Subject: Re: problems assessing disk size with ahcisata
To: David Laight <>
From: Steven M. Bellovin <>
List: current-users
Date: 11/05/2007 12:47:41
On Mon, 5 Nov 2007 08:02:09 +0000
David Laight <> wrote:

> On Mon, Nov 05, 2007 at 05:56:09AM +0000, Steven M. Bellovin wrote:
> > I just ran into a serious problem with a new Thinkpad T61: anything
> > looking at the MBR on the 160G disk running with ahcisata got very
> > confused.  I'll skip all the gory details (and the state it left my
> > disk in); the net, though, is the fdisk and sysinst think the drive
> > has only 67MB.  When I changed it in the BIOS to compatibility
> > mode, it picked up the size correctly.
> What does 'sysctl machdep.diskinfo' show?
> 	David
This is what it shows when running in compatibility mode:
machdep.diskinfo: 80:312581808(1023/240/63),2  wd0:80

If you want, I'll reboot with SATA set.

I don't know what the 80 means; the rest is obviously the geometry, and
that was displayed correctly during sysinst's request that I verify it.

		--Steve Bellovin,