Grub 2 recovery

1. Boot into Live CD 2. Enter the following commands:

sudo fdisk -l

And find your Ubuntu partition

3. Run the following commands:

sudo mount /dev/sda2 /mnt

sudo mount --bind /sys /mnt/sys

sudo mount --bind /proc /mnt/proc

sudo mount --bind /dev /mnt/dev

sudo chroot /mnt

4. Now reinstall Grub2

grub-install --recheck /dev/sda

apt-get install --reinstall grub2

5. Run as root

update-grub2

since in the previous steps the grub list was created with an /dev/sda4 as an entry.

These are the commands for managing Grub 2. 1. Check the file /etc/default/grub and adjust the options accordingly 2. Install grub2 in MBR

grub-install /dev/sda

3. Auto-generate the boot menu for grub2:

grub-mkconfig -o /boot/grub/grub.cfg

4. Update the setup menu file:

update-grub

5. For recovering a node in guane run:

grub-mkconfig -o /boot/grub/grub.cfg

grub-install /dev/sda