New warning, what does it mean?

[M. Warner Losh]

In message: <A77633F1-893A-4BFD-9DF1-E423E79458CB at mac.com>
            Marcel Moolenaar <xcllnt at mac.com> writes:
: 
: On Jan 2, 2009, at 10:54 AM, M. Warner Losh wrote:
: 
: > I'm getting the following from my main disk on boot now:
: >
: > GEOM: ad0s2: geometry does not match label (255h,63s != 16h,63s).
: >
: > What does it mean?  This system is a dual-boot FreeBSD/Windows
: > laptop.  In the past I've seen sysinstall barf on the former geometry,
: > and have had problems installing dual-boot core4/FreeBSD systems
: > because of it.
: >
: > In addition, the above error message is useless.  Who is complaining?
: > Why are they complaining?  What is the corrective action to be taken
: > here?  Why does it matter with modern disks and BIOSes anyway?
: 
: This is geom_part telling you that the BSD disk label does
: not have the same geometry as ad0 is telling it it has.
: Your label claims 255 heads. Your disk claims 16 heads.
: There's nothing you need to do at this time.

It would be nice to know which of the numbers is which...  You can't
tell that without finding this message in the source...

Warner