In step 1, we list all the available snapshots for the kvm1 virtual machine. In steps 2 and 3, we obtain information about the snapshots. Of particular interest is the Parent and Children fields, showing us the hierarchy of the snapshots.
In step 4, we examine the XML definition of the KVM guest and the disk-only, external snapshot. We can observe the snapshot='external' type and the base image location specified with the <source file='/var/lib/libvirt/images/kvm1_disk_external.qcow2'/> stanza.