Booting FreeBSD 8.0-RC1 from usb stick

[Marius Nünnerich]

Hi all,

FreeBSD 8.0-RC1 was installed onto hard disk. The root filesystem was
transferred to a usb memory stick via
#pwd
/
# find -print . -x | cpio -pdm /mnt/usbstick

The fstab on the stick was modified such that "/" was to be mounted
from /dev/da0s1a, the ufs fs on the usb stick.
This had proven to work perfectly with 7.2.
In 8.0-RC1, however, this approach fails. After booting the kernel,
the system does not automatically mount the "/" partition. Instead, it
asks for a partition to mount to "/", and when exactly the same
location is entered ("ufs:/dev/da0s1a"), it mounts this partition and
works perfectly.
Explicitly setting the root partition
(vfs.root.mountfrom="ufs:/dev/da0s1a") in /boot/loader.conf does not
help either: Again, the system knows which partition it should mount
to "/", but it fails to do so. (vfs.root.mountfrom.options=rw was set
too).

Any ideas?
Marius