I have the same problem with kernel 2.6.15-21-amd64-generic, whereas the previous kernel 2.6.15-20-amd64-generic boots.
Booting the kernel. Unable to find volume group "Ubuntu" ALERT! /dev/mapper/Ubuntu-root does not exist. Dropping to a shell!
I booted using the previous kernel, and checked the version of initramfs-tools 0.40ubuntu29.
Please let me know if you require additional information.
I have the same problem with kernel 2.6.15- 21-amd64- generic, whereas the previous kernel 2.6.15- 20-amd64- generic boots.
Booting the kernel. Ubuntu- root does not exist. Dropping to a shell!
Unable to find volume group "Ubuntu"
ALERT! /dev/mapper/
I booted using the previous kernel, and checked the version of initramfs-tools 0.40ubuntu29.
Please let me know if you require additional information.