Whoops.

To all of you who have root on LVM:

Do not assume it is a good idea to make a snapshot of your current root volume and then to reboot with that as root. Unless you have dm-snapshot compiled in your kernel or on your initrd, it will not work.

In an unrelated message, I'm writing a bootable CD for my desktop right now, because it won't boot currently.

Hmm, maybe they are related after all.

Next time, I'll just boot with /bin/bash as my shell, and pivot_root into the snapshot device (which I will then create on the fly). That should work.