Ubuntu disk partition extension under LVM:
1/ extend the LVM volume (cheated with gparted but parted would work fine, this is the container partition for the “Volume Group”.
2/ Next launch LVM and use “lvdisplay” to print the current output, mine was a container group with a single logical volume named “root”
3/ Now I know the location and name of the LV I can issue the following command to expand it into the available free space created in step 1:
lvextend -l +100%FREE /dev/Container1/root
4/ Finally exit lvm and expand the file system to fill the LV:
sudo resize2fs /dev/Container1/root