5.6 Snapshots of KVM guests using UEFI fail and are unsupported

You cannot do snapshots of KVM guests if they use UEFI. In older versions of QEMU and libvirt, the tools may allow you to create the snapshot without an error or warning, but the snapshot could be corrupted. More recent versions of these tools prevent snapshot creation with an error. For example:

virsh # snapshot-create-as OL7-seboot
error: Operation not supported: internal snapshots of a VM with pflash based
firmware are not supported

(Bug ID 26826800)