Resize-Extend a disk partition with unallocated disk space in Linux – CentOS, RHEL, Ubuntu, Debian & more Step 1: Alter the Partition Table. Boot From CD or USB Drive If you have the CD or USB drive you installed Ubuntu from, you can insert it into your computer and restart. GParted is a full-featured, graphical partition editor that acts as a frontend to a variety of Linux terminal commands. vgdisplay will now show that the volume group size is 30Gb. The Ubuntu live CD includes the GParted partition editor, which can modify your partitions. Extend the LVM Logical Volume In order to extend the logical volume, you need the logical volume path which is available from lvdisplay. Run ‘vgextend ubuntu-vg /dev/sda3’ to extend the existing volume group to also use sda3. Step 2: Reboot.