Update: By following this post: http://askubuntu.com/questions/59487...rypt-partition I was able to make some progress, but I haven't still been able to boot my system. I edited my /etc/crypttab like so:
"LABEL" being the label of the USB drive that also contains the /boot partition. These are the messages I get at boot time:
sda1_crypt UUID=(...) /dev/disk/by-label/LABEL:/keyfile luks,keyscript=/lib/cryptsetup/scripts/passdev
So I'm guessing I need to find a way to make the luks LVM volume available at boot time.
Volume group "luks" not found Skipping volume group luks Unable to find LVM volume luks/xxxxxxxxx cryptsetup: sda1_crypt set up successfully Gave up waiting for root device. Common problems: -Boot args (cat/proc/cmdline) -Check rootdelay = (did the system wait long enough?) -Check root = (did the system wait for the right device?) -Missing modules (cat/proc/modules; ls /dev) ALERT! /dev/mapper/luks-XXXXXXXXXXXXXXX does not exist. Dropping to a shell!