I think it may be caused by the fact that grub-install does not know
where is the root directory (the partition where /boot/grub is located on).
maybe something like :
sudo mount /dev/sda1 /mnt # where sdb1 is your root partition (or
boot partition if you have one)
sudo grub-install /dev/sda --root-directory=/mnt # sda is the disk
where you want to install grub
Or maybe you can do a chroot :
sudo mount /dev/sda1 /mnt # root partition (or boot partition)
sudo mount -o bind /dev /mnt/dev
sudo mount -o bind /proc /mnt/proc
sudo mount -o bind /sys /mnt/sys
sudo chroot /mnt
grub-install /dev/sda # where you want to install grub
I think it may be caused by the fact that grub-install does not know
where is the root directory (the partition where /boot/grub is located on).
maybe something like : directory= /mnt # sda is the disk
sudo mount /dev/sda1 /mnt # where sdb1 is your root partition (or
boot partition if you have one)
sudo grub-install /dev/sda --root-
where you want to install grub
Or maybe you can do a chroot :
sudo mount /dev/sda1 /mnt # root partition (or boot partition)
sudo mount -o bind /dev /mnt/dev
sudo mount -o bind /proc /mnt/proc
sudo mount -o bind /sys /mnt/sys
sudo chroot /mnt
grub-install /dev/sda # where you want to install grub
Hope it can help someone if it works.