I am trying to set up a usb hard drive to dual boot 32-bit ubuntu and 64-bit ubuntu in separate partitions, while sharing a /home partition. The 32-bit version works fine (it was installed first), but after installing the 64-bit version in a new partition, I crash on booting into it.

The output is:

Code:
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; Is /dev)
ALERT! /dev/disk/by-uuid/5cf1b255-86f8-4924-901b-ebe7662da8d5 does not exist. Dropping to a shell!
When I try to find the hard drive containing the ubuntu partitions, it does not show up in blkid, nor in any of the /dev/disk/by-X folders.

In dmesg i find the following problem which seems to indicate why I can't find the usb hard drive:

Code:
unable to enumerate USB device on port 2
Even though the 32 bit partition has no problem booting.

I ran update-grub and checked the entries, the only differences are that the 32-bit version has insmod gzio, recordfail, and sets the gfx.