grub-install /dev/sda
grub-install –recheck /dev/sda
grub> device (hd0) /dev/sda
grub> root (hd0,0)
grub> setup (hd0)
grub-install /dev/sdagrub-install /dev/sda grub-install --recheck /dev/sda grub> device (hd0) /dev/sda grub> root (hd0,0) grub> setup (hd0)