root@xubuntu:/# sudo update-grub
sudo: unable to resolve host xubuntu
Generating grub.cfg ...
Found linux image: /boot/vmlinuz-3.11.0-13-generic
Found initrd image: /boot/initrd.img-3.11.0-13-generic
Found linux image: /boot/vmlinuz-3.11.0-12-generic
Found initrd image: /boot/initrd.img-3.11.0-12-generic
Found memtest86+ image: /boot/memtest86+.bin
grub-probe: error: cannot find a GRUB drive for /dev/sdb1.  Check your device.map.
Found Windows 8 (loader) on /dev/sda1
done
root@xubuntu:/#