Recovering From GRUB Failures

Sometimes life belches and GRUB fails to function. Here are some basic steps toward recovery.

1. Boot with a Live ISO, preferably the same as the operating system.
2. Launch a terminal window.
3. Elevate privileges: sudo su -
4. mkdir /mnt/chroot

Discover which hard disk partition is the system partition.

1. mount /dev/sdaX /mnt/chroot where X is the system partition.
2. mount --bind /dev /mnt/chroot/dev
3. mount --bind /proc /mnt/chroot/proc
4. mount --bind /sys /mnt/chroot/sys
5. mount --bind /tmp /mnt/chroot/tmp

If there are no error messages then chroot into the hard disk system partition.

chroot /mnt/chroot

At this point access to the installed system is available, almost as though booting with a good GRUB boot menu.

Restore GRUB:

1. Mount all partitions: mount -a
2. Update GRUB: update-grub
3. Install GRUB: grub-install
4. Update the initrd: update-initramfs -u
5. Exit the chroot: exit

Reboot. Hopefully GRUB is repaired.

Posted: June 22, 2020 Category: Usability Tagged: General

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