Question

0

Ubuntu fails to boot after Partition was moved | Superblock not found by GRUB

rated 0 times [ 0] [ 0] / answers: 1 / hits: 1000 / 2 Years ago, sun, september 18, 2022, 9:07:00

My current situation;

I have tried to shrink down C: and add the resulting space to my Ubuntu partition. I've done this using Windows (which was probably the biggest mistake) and in the process I moved the "unallocated" space from the end of C: to the beginning of the Ubuntu Partition (the one with filesystem Ext4).

Apparently Ubuntu does not boot anymore because the superblock is not found by GRUB. The partition is not mountable due to possible corruption on a live Ubuntu I bootet to. HELP

Question; How can I repair GRUB on my Ubuntu 20.04?

Edit; Boot Repair info

Answers

Only authorized users can answer the question. Please sign in first, or register a free account.

throecember

Add To Favorites

Follow

Total Points: 274

Total Questions: 118

Total Answers: 132

Location: India

Member since Thu, Jun 11, 2020

4 Years ago

throecember questions

1 How will Ubuntu handle battery replacement in a laptop?

Thu, Jun 23, 22, 04:57, 2 Years ago

1 Getting grub menu to work on dual boot Ubuntu 22.04 Windows 11. Currently boots in a loop

Fri, Dec 17, 21, 07:26, 2 Years ago

1 Installing Ubuntu 20.04.02 Live ISO on Windows 2019 Hyper-V

Fri, Nov 12, 21, 07:06, 3 Years ago

1 Unable to update any package on Ubuntu 20.10 because of package linux-modules-extra-5.8.0-31-generic

Fri, May 12, 23, 04:34, 1 Year ago

1 Firefox stopped playing videos in Ubuntu 20.04

Thu, Apr 20, 23, 18:10, 1 Year ago

View All

answered 2 Years ago antoccasiona · Accepted Answer

Who believes this?! I was successfully by running fsck
If you still can, only proceed with a Backup

1); List your disks with

sudo sfdisk -l

2); Find the one with your boot on it. In my case /dev/nvme0n1p6 (could be /dev/sdaX for you)

Device      Start        End          Sectors      Size   Type

/dev/nvme0n1p1      2048    923647    921600   450M Windows-Recovery

/dev/nvme0n1p2    923648   1126399    202752    99M EFI-System

/dev/nvme0n1p3   1126400   1159167     32768    16M Microsoft reserved

/dev/nvme0n1p4   1159168 817598519 816439352 389,3G Microsoft Basis

/dev/nvme0n1p5 817600512 818739199   1138688   556M Windows-Recovery

/dev/nvme0n1p6 818741248 974942207 156200960  74,5G Linux-Filesystem

/dev/nvme0n1p7 974942208 974991359     49152    24M BIOS boot

/dev/nvme0n1p8 974993408 976771071   1777664   868M Windows-Recovery

Use fsck to check for errors

sudo fsck /dev/nvme0n1p6

use additional -y flag after 'sudo' to try fix all errors immediatly.

try booting

If you get something like;

Bad magic number in super-block while trying to open /dev/sda2

The superblock could not be read or does not describe a valid ext2/ext3/ext4 



filesystem....you might try running e2fsck with an alternate superblock:



e2fsck -b 8193 <device>

or

e2fsck -b 32768 <device>

(Backup first - also any other OS partition)

You can try to

e2fsck -b 8193 /dev/sda

or

e2fsck -b 32768 /dev/sda