I was executing the following command to lively migrate local storage to network storage,

[root@192-168-152-51 ~]# virsh blockcopy a75056a4-44e0-4b97-bc77-78142ee17038 vda —xml rbd.xml —wait —verbose —pivot
error: argument unsupported: non-file destination not supported yet

but I get the following error:

error: argument unsupported: non-file destination not supported yet

I check my libvirt source code, and find the following code sniff in qemuDomainBlockCopyCommon function

    if (!virStorageSourceIsLocalStorage(mirror)) {
        virReportError(VIR_ERR_ARGUMENT_UNSUPPORTED, "%s",
                       _("non-file destination not supported yet"));
    }

it was introduced by Eric.

commit e53ee6c123321a1775ef3b36e15a5fa351d10fe4
Author: Eric Blake eblake@redhat.com
Date: Fri Aug 29 16:30:46 2014 -0600

blockcopy: tweak how rebase calls into copy

So my question is that why we cannot block copy to network storage?