On Tue, Jan 12, 2016 at 10:01 PM, Richard W.M. Jones <rjones@redhat.com> wrote:
 - libvirt is way more complex and fails much more frequently :-(

It's unfortunately because of the last point that if libvirt fails to
start the qemu appliance, we print an error message telling you to try
with LIBGUESTFS_BACKEND=direct.


That was one of the motivations. You were hit by it too apparently (https://bugzilla.redhat.com/show_bug.cgi?id=1271183 ).

I removed the connect line and set the environment variable and all looks good. I indeed don't see any much different performance difference.

Thanks!
Y.