CloneZilla works perfectly. It produces small image files, has integrity check and works fast. If you want to use third device as image repository you should choose device-image when creating image of the first disk and then image-device when you restore it to second disk. If you want to use only two disks - you should use device-device mode. Optionally you may want generate new UUIDs, SSH-key (if SSH server installed), and change hostname.