Also observed on a Thinkpad T440p running 14.04.1 64-bit Xubuntu. The system previously booted without any issue, but after bringing all packages up to date today booting results in the missing xubuntu--vg-root error. Booting into recovery mode and resuming circumvents the problem. Tried reinstalling linux-image-3.13.0-36-generic to force a rebuild of the boot ram disk image, but that didn't seem to have any effect.
Also observed on a Thinkpad T440p running 14.04.1 64-bit Xubuntu. The system previously booted without any issue, but after bringing all packages up to date today booting results in the missing xubuntu--vg-root error. Booting into recovery mode and resuming circumvents the problem. Tried reinstalling linux-image- 3.13.0- 36-generic to force a rebuild of the boot ram disk image, but that didn't seem to have any effect.