I have one single LVM with Ubuntu MATE installed as my only OS (see pic) which I wish to split into two, one for the OS and one for my data. I have tried to re-partition from the live USB using GParted but am unable to unmount the volume. If I close GParted I can eject/unmount from the file explorer, but then when I open Gparted again the volumes are locked (with the key icon) and have disappeared from the file explorer menu.
I would appreciate any help with this.
Thanks (hopefully) in advance.