Mounting errors

When a Ext4 filesystem stopped to mount properly enter in a terminal:

dmesg | tail

If the result is: "EXT4-fs (sda1): group descriptors corrupted!"

Check for backup superblocks, replace the x’s with your partition name

sudo mke2fs -n /dev/sda1

"Superblock backups stored on blocks:

32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208"

Restore the superblock from the backup, again replacing the x’s with your partition name, and block_number with the first backup superblock

sudo e2fsck -b block_number /dev/sda1

replace sda1 with the drive it is concerning.