If Grub is missing after installing Ubuntu and screen is showing Grub Rescue, then Ubuntu grub rescue or restore has to done. It can be done through Ubuntu Server CD or Ubuntu Desktop CD.
If at system start up you might be seeing the option Grub Rescue or Grub missing option then you need to follow the below commands.
If you don’t have the desktop CD then you can use Ubuntu server CD or USB also.
NOTE: You will get /usr/sbin/grub-probe: error: cannot stat ‘aufs’ error if you didn’t follow the commands listed below. Specifically you did not do chroot,
i.e. sudo chroot /mnt.
For Ubuntu grub rescue follow these steps:
1.Boot from the Ubuntu Desktop live CD.
|Ubuntu grub rescue-1|
|Ubuntu grub rescue screenshot-2|
The partation which have Linux under System column is your drive in which ubuntu linux is installed. In screenshot ubuntu partition drive is /dev/sda11.
4. Mount the ubuntu partition drive
sudo mount /dev/sdXX /mnt (example ‘sudo mount /dev/sda11 /mnt’ ,don’t miss the spaces.)
5.Only if you have a separate boot partition:
sudo mount –bind /dev /mnt/dev
sudo mount –bind /sys /mnt/sys
7. To ensure that only the grub utilities from the LiveCD get executed, mount /usr
sudo mount –bind /usr/ /mnt/usr
sudo chroot /mnt
8. If there is no /boot/grub/grub.cfg or it’s not correct, create one using
grub-install /dev/sdX (e.g. grub-install /dev/sda. Do not specify the partition number.
sudo grub-install –recheck /dev/sdX
sudo umount /mnt/dev
sudo umount /mnt/proc
sudo umount /mnt/sys
If you mounted a separate /boot partition:
sudo umount /mnt/boot
13. Unmount the LiveCD’s /usr directory:
sudo umount /mnt/usr
14. Unmount last device:
sudo umount /mnt
NOTE: If you are getting /usr/sbin/grub-probe: error: cannot stat ‘aufs’ error then the possible reason is that you didn’t follow the commands listed above. Specifically you did not do chroot,
ie sudo chroot /mnt.
Follow the above steps correctly and you are done.