Can't mount disk (VFS: Can't find ext4 filesystem)

Solution 1:

When using mount you have to mount the partition not the drive itself eg mount -t ext4 /dev/sda1 /data

Solution 2:

You can get that error in the dmesg when you are creating a new Logical Volume but you forget to run the mkfs command which actually builds the file system. What I am trying to say here is that in order to be able to mount a partition you should make sure first that you ran mkfs after you created the Logical Volume or else it will complain same as in your example.

1. Create a Logical Volume from the Volume group vg: lvcreate -L 2G --name lv_data vg
2. Make the file system an ext4 type: mkfs.ext4 /dev/mapper/vg-lv_data
3. Mount it: mount -t ext4 /dev/mapper/vg-lv_data /data

Jumping/missing step 2 it will complain with the error: VFS: Can't find ext4 filesystem.

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Solution 3:

It clearly says wrong file system type, give below command and check which file system it is.

file -sL /dev/mapper/datavg-datalv

output:

/dev/mapper/datavg-datalv: SGI XFS filesystem data

Cross check the fs type in /etc/fstab, if it is other than xfs, change it to xfs and in /etc/fstab and then try mounting