[libvirt] virStorageVolCreateXMLFrom

I'd like to get a better understanding of the virStorageVolCreateXMLFrom api Its name and signature imply that it is a cloning operation that copies a volume from one location to another. Is this correct? Assuming that the answer is yes I have few other questions: Does it support remote copy of non-shared storage, e.g. from a http server? Is there any thought about adding digest validation check, e.g. with a md5 digest? Is copy-on-write cloning supported in this command? Kenneth Nagin