root@mint:/# update-grub
Generating grub.cfg ...
using custom appearance settings
Found Linux Mint 16 Petra (16) on /dev/sdb6
Found Linux Mint 15 Olivia (15) on /dev/sdc1
Found linux image: /boot/vmlinuz-3.11.0-24-generic
Found initrd image: /boot/initrd.img-3.11.0-24-generic
Found linux image: /boot/vmlinuz-3.2.0-65-generic
Found initrd image: /boot/initrd.img-3.2.0-65-generic
Found linux image: /boot/vmlinuz-3.11.0-24-generic
Found initrd image: /boot/initrd.img-3.11.0-24-generic
Found linux image: /boot/vmlinuz-3.2.0-65-generic
Found initrd image: /boot/initrd.img-3.2.0-65-generic
done