Reinstalar GRUB com CHROOT ( Reinstall GRUB with CHROOT )

CHROOT – GRUB
zumm@destino :~$ sudo -i
root@destino :~# mkdir /mnt/chroot
root@destino :~# mount /dev/sda1 /mnt/chroot
root@destino :~# mount -o bind /dev /mnt/chroot/dev
root@destino :~# mount -o bind /sys /mnt/chroot/sys
root@destino :~# mount -o bind /proc /mnt/chroot/proc
root@destino :~# chroot /mnt/chroot
root@destino :/# update-grub
root@destino:/# grub-install /dev/sdb