The QCOW2 format is the most powerful format supported by KVM-QEMU. It does not pre-allocate disk space, it offers the ability to create snapshots and, later, you can create new images that use a previous image as a base to dramatically speed-up the setup of a future VM. In this article we will look at some of the advanced features available in the QCOW2 format through the QEMU Image tool. We create a QCOW2 image, create snapshots within the image, create an image that is based on a backing file and copy an image to get rid of the reference to the backing file.