How to confuse geom_part_mbr

While installing 8.0-RC2 via a netbooted 7.0-RELEASE:

# fdisk -I -B ad0
# bsdlabel -rw ad0 auto
# bsdlabel -e ad0
[hmm, that wasn't right!]
# fdisk -I -B ad0
# bsdlabel -rw ad0s1 auto
# bsdlabel -e ad0s1
# bsdlabel -B ad0s1a
# newfs -U -L root ad0s1a
# mount /dev/ufs/root /mnt
[install to /mnt]
# reboot

The machine won't boot, even though you have a valid partition table on
ad0 that points to a valid bsdlabel in ad0s1.  The only way to fix it is
to zero the first few sectors of ad0 and re-run fdisk.

(yes, I know I should update my nfsroot)

DES
-- 
Dag-Erling Smørgrav - des_at_des.no