After boot password entry I can see the following on the screen:
mounting /dev on /root/dev failed: No such file or directory. mounting /sys on /root/sys failed: No such file or directory. mounting /proc on /root/proc failed: No such file or directory. Target filesystem doesn't have /sbin/init. No init found. Try passing init=bootarg. then the busybox stuff. (Ubuntu 1:1.13.3-1 ubuntu 11) built-in shell (ash).
I saw this problem asked and solved for someone in 2010 but the instructions there didn't work for me.