Same problem here. root on LVM, boot hangs on "waiting for root filesystem". Also, my home is on LVM, which doesn't get mounted because the fstab was converted to UUIDs, and for my LVM Volumes, no entries in /dev/disk/by-uuid/ get created.
** Bug 54189 has been marked a duplicate of this bug -- LVM/MD root filesystem not found by uuid https://launchpad.net/bugs/54002 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
