lvm

Check the physical volumes

pvs

Check the volume groups

vgs

Check the logical volumes

lvs

Display volume group details

vgdisplay

Create the additional logical volume

lvcreate -l 663940 -n plot01 ubuntu-vg

Create filesystem

mkfs.ext4 /dev/ubuntu-vg/plot01

Get the new UUID

blkid

Add it to fstab

vim /etc/fstab