Comment 6 for bug 120504

We hit this too

 * Brand new HP ML 115 G1 Server with 2 x SATA disks, SBS Bundle ;-)
 * Fiesty Alternate install with AMD64
 * On each drive: /boot partition 100mb , Raid 1 partition huge , Swap partition 1gb
 * LVM on Raid
 * Everything else in install as default

To fix, boot to Fiesty live CD

Install mdadm with
 * sudo apt-get install mdadm

Install LVM with
 * sudo apt-get install lvm2

Start LVM
 * sudo /etc/init.d/lvm start

Make a mount point
 * sudo mkdir /mnt/newroot

Mount your new system
 * sudo mount /dev/vg0/lv0 /mnt/newroot

Edit fstab in the new system, to change from UUID to device
 * sudo nano /mnt/newroot/etc/fstab
Change the UUID to /dev/sda1 for the /boot mount point.

It will now start, might grizzle, but at least your up and running , and can sort out the issues with a working system.