Can't mount disk (VFS: Can't find ext4 filesystem)
When using mount you have to mount the partition not the drive itself eg
mount -t ext4 /dev/sda1 /data
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.
- Create a Logical Volume from the Volume group vg: lvcreate -L 2G --name lv_data vg
- Make the file system an ext4 type: mkfs.ext4 /dev/mapper/vg-lv_data
- 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.
It clearly says wrong file system type, give below command and check which file system it is.
file -sL /dev/mapper/datavg-datalv
/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