liveCD启动

sudo mount /dev/sda1 /mnt
sudo mount /dev/sba1 /mnt/home
sudo mount --bind /dev/ /mnt/dev
sudo mount --bind /proc/ /mnt/proc
sudo mount --bind /sys/ /mnt/sys
sudo chroot /mnt
grub-install /dev/sda1
update-grub

重启完事……