July 23, 2018 - Reading time: ~1 minute

BusyBox v1.18.5 (Ubuntu 1:1.18.5-1ubuntu4) built-in shell (ash) 
Enter 'help' for a list of built-in commands.

(initramfs) exit

/dev/mapper/ubuntu--vg-root: UNEXPECTED INCONSISTENCY; RUN fsck MANUALLY.
(i.e., without -a or -p options) 
fsck exited with status code 4. 
The root filesystem on /dev/mapper/ubuntu--vg-root requires a manual fsck. 

BusyBox v1.18.5 (Ubuntu 1:1.18.5-1ubuntu4) built-in shell (ash)
Enter 'help' for a list of built-in commands.

(initramfs) fsck /dev/mapper/ubuntu--vg-root -y

fsck from util-linux 2.27.1
e2fsck 1.42.13 (17-May-2015)
/dev/mapper/ubuntu--vg-root contains a file system with errors, check forced.

BusyBox v1.18.5 (Ubuntu 1:1.18.5-1ubuntu4) built-in shell (ash)
Enter 'help' for a list of built-in commands.

(initramfs) reboot

January 18, 2017 - Reading time: 8 minutes

First, figure out what partition we’re dealing with.

sudo fdisk -l


The above will list all the partitions on all the drives in your computer. To recover a lost partition, your going to need Testdisk. Testdisk is included in Parted Magic, and there’s a great guide on their site. For this though, we just need the partition number, such as /dev/sda3 or /dev/hdb1. Now, make sure your superblock is the problem, by starting a filesystem check, replacing xxx with your partition name. Here, you can change ext4 to ext3, or ext2 to suit the filesystem.

1	sudo fsck.ext4 -v /dev/xxx

If your superblock is corrupt, the output will look like this

1 2 3 4 5 6 7 8 9 10 11

fsck /dev/sda5 fsck 1.41.4 (27-Jan-2009) e2fsck 1.41.4 (27-Jan-2009) fsck.ext4: Group descriptors look bad... trying backup blocks... fsck.ext4: Bad magic number in super-block while trying to open /dev/sda5   The superblock could not be read or does not describe a correct ext4 filesystem.  If the device is valid and it really contains an ext4 filesystem (and not swap or ufs or something else), then the superblock is corrupt, and you might try running e2fsck with an alternate superblock: e2fsck -b 8193 <device>

Now lets find where your superblock backups are kept.

1	sudo mke2fs -n /dev/xxx

Down at the bottom of this output, should be a list of the backups

 

1 2	Superblock backups stored on blocks: 32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208

Your almost there. Finally, restore the superblock from the backup, again replacing the x’s with your partition name, and block_number with the first backup superblock.