# http://www.webupd8.org/2014/01/how-to-fix-non-bootable-ubuntu-system.html
sudo mkdir /mnt/
sudo mount /dev/mint-vg/root /mnt

# # # following command is CRITICAL! Otherwise you won't edit the correct config file
sudo mount /dev/sda1 /mnt/boot
# ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^

sudo mount /dev/mint-vg/home /mnt/home
for p in /sys /proc /run /dev /dev/pts; do sudo mount --bind "$p" "/mnt$p"; done
sudo cp /etc/resolv.conf /mnt/etc/
sudo chroot /mnt