Comment 12 for bug 1334398

@Ken'ichi, per comment 8, it's a pretty intensive setup:

http://git.openstack.org/cgit/openstack/tempest/tree/tempest/api/compute/images/test_list_image_filters.py#n29

The setup creates 2 servers and then 3 snapshots from those 2 servers, and the JSON and XML test classes are running concurrently, so we could be creating multiple snapshots concurrently which is in theory overloading libvirt/qemu and causing the connection reset with libvirt.