ubuntu@ubuntu:~$ sudo mount /dev/sda2 /mnt
ubuntu@ubuntu:~$ sudo mount -o bind /dev /mnt/dev
ubuntu@ubuntu:~$ sudo mount -o bind /sys /mnt/sys
ubuntu@ubuntu:~$ sudo mount -t proc /proc /mnt/proc
ubuntu@ubuntu:~$ sudo cp /proc/mounts /mnt/etc/mtab
ubuntu@ubuntu:~$ sudo chroot /mnt /bin/bash
root@ubuntu:/# grub-install /dev/sda
/dev/sda does not have any corresponding BIOS drive.
root@ubuntu:/# grub-install --recheck /dev/sda
Probing devices to guess BIOS drives. This may take a long time.
Could not find device for /boot: Not found or not a block device.
root@ubuntu:/#