How to View Free Disk Space and Disk Usage From the Linux Terminal

https://www.howtogeek.com/409611/how-to-view-free-disk-space-and-disk-usage-from-the-linux-terminal/

Size viewed with GParted and that with df are different

https://askubuntu.com/questions/401503/resized-partition-with-gparted-size-with-df-h

 

Try running

 lvextend -L +1G /dev/mapper/kvg-root

the +1G is however much space you are adding. Try doing +9G.

then do

 sudo resize2fs /dev/mapper/kvg-root