partitioning - How to resize / and add another logical volume without data loss

Ubuntu 16.04 installed with these settings "Erase Disk and install Ubuntu" with "Use LVM with the new Ubuntu installation". Now have 3 partitions:

• /dev/sda1 mounted as /boot/efi


• /dev/sda2 Linux file system mounted as /boot and



• /dev/sda3 Linux LVM as 255 GB LVM2 PV with inside 2 Logical Volume /dev/ubuntu-vg/root (247 GB) and /dev/ubuntu-vg/swap_1 (8,5 GB).

Have searched for a clear and safe tutorial to be able to safely shrink the root partition to something like 30 GB (more or less) and create a new Logical Volume with the rest for a home/data partition.

Can't use system-config-lvm because of an error. The GUI shows up but doesn't display anything:

Unable to show VG because it contains features that are not supported in current version of system-config-lvm.

So I need to use the command line but not sure if it takes care of the data on the root partition (got a backup of important data).

Can anybody give me directions on what to do?