tantosoft.com

Grub Rescue Commands

Varias veces he necesitado reparar el gestor de arranque del sistema operativo Linux, GRUB, actualmente GRUB2. Actualmente con distribuciones como Ubuntu o similaries, es casi pan comido, pero dejo aquí un para de entradas sacadas de la web, para que queden en mi memoria y os sirvan si alguna vez os hace falta:

 Grub Rescue commands.

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. At system start up you might seeing the option Grub Rescue or Grub missing.

This article will show how to do Ubuntu grub rescue with screen shots using Ubuntu Desktop CD. These screenshoats of Ubuntu grub rescue has been taken on Ubuntu 11.04. The very same method can be used to repair grub mint Debian.

If you don't have the desktop CD then Ubuntu Grub can also be rescue from Ubuntu server CD or USB. See here for Ubuntu Grub rescue or restore from Ubuntu server CD.

To do grub rescue through Ubuntu Server CD see

"Install Grub from Ubuntu server CD".

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,
ie sudo chroot /mnt

For Ubuntu grub rescue follow these steps:
1.Boot from the Ubuntu Desktop live CD

Ubuntu grub rescue-1

Select Try Ubuntu.     


2.In Live Desktop session open terminal. 
Application ->Accessories->Terminal.


3. In Terminal tpye sudo fdisk -l.
It will display all partiton of the disk.

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 /dev/sdYY /mnt/boot.
6.  Mount the virtual filesystems:

sudo mount --bind /dev /mnt/dev
sudo mount --bind /proc /mnt/proc
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 
update-grub
or  update-grub2
9.Now reinstall Grub
grub-install /dev/sdX (eg. grub-install  /dev/sdaDo not specify the partition number.
10. Verify the install 
sudo grub-install --recheck /dev/sdX
11. Exit chroot : CTRL-D on keyboard.
12. Unmount virtual filesystems:
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

15. Reboot.
sudo reboot.

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.

Quiere contactar con nosotros?

Envíenos un Esta dirección de correo electrónico está siendo protegida contra los robots de spam. Necesita tener JavaScript habilitado para poder verlo. o llámenos a (+34) 698 259 856