If you are at the point where getty is attempting to run, then you're clearly multi-user.
If you have a filesystem that is supposed to be wd0 but is currently wd2 and that's where it booted from, the obvious thing to look for is what is in /etc/fstab - you said that /usr (and /var) are mounted filesystems. That means they're being nounted according to what is in fstab. If that says wd0X /usr ... then it will not be mounting the one from wd2 that you want it to be using. Those things all need to be wd2 instead. But then when it is installed in the real system as wd0 they all need to be changed back again. I'd start looking there (as maya@ said, /usr is needed to run the simplest of binaries, even though all the files are often on /) kre