user@host ~ $ mkdir /mnt/tmp user@host ~ $ mount /dev/sda3 /mnt/tmp user@host ~ $ mount -o bind /dev /mnt/tmp/dev user@host ~ $ mount -t proc none /mnt/tmp/proc user@host ~ $ mount -o bind /sys /mnt/tmp/sys user@host ~ $ chroot /mnt/tmp (chroot) user@host ~ $ update-grub2 (chroot) user@host ~ $ exit