[robespierre]

Well, is it possible that "var" is the name of the directory that you moved? If so, what must be done is find out where it moved to, and then move it back.

Going back to the miniroot, if you type
shroot find / -name var -type d -prune

the command should print the full path of every directory named "var". Let's suppose that there was only one result printed, and it was "/home/nero/var".
then still from the miniroot, you would type
shroot mv /home/nero/var /

If the result printed was, however, just "/var", then the theory of which directory got moved appears disproven. If multiple results were printed, you would need to investigate further to see which one looked like "the var directory that belongs at /var", which is a little difficult to explain. (it should have subdirectories adm, spool, log, tmp, ...)

"Initialize a disk" erases all of the data.

edit:
If you can mount the disk from your Onyx, you can of course do the changes from it, as well.
Just use "chroot /disk2" where you would say "shroot" from the miniroot inst> prompt.