Comment 3 for bug 1901739

So, this seems to be due to back-n-forth live migration (without shared storage) of a paused instance — I don't see what is the purpose of this (although, I can make up an imaginary rationale.)

That said, the error makes sense ... due to the missing block device data the 'drive-mirror' (which does the copy) got cancelled, and in turn the NBD copy got cancelled too.

Still digging the cause, though.

(Since the Gate logs might go away, I've collected the important source and destination libvirt/QEMU logs here: https://kashyapc.fedorapeople.org/LP-1901739/)