The n-cpu logs have several errors for the libvirt connection being reset:

http://logs.openstack.org/70/97670/5/check/check-tempest-dsvm-postgres-full/7d4c7cf/logs/screen-n-cpu.txt.gz?level=TRACE#_2014-06-24_22_54_52_973

2014-06-24 22:54:52.973 16186 TRACE nova.compute.manager [instance: 90c79adf-4df1-497c-a786-13bdc5cca98d] Traceback (most recent call last):
2014-06-24 22:54:52.973 16186 TRACE nova.compute.manager [instance: 90c79adf-4df1-497c-a786-13bdc5cca98d]   File "/opt/stack/new/nova/nova/compute/manager.py", line 352, in decorated_function
2014-06-24 22:54:52.973 16186 TRACE nova.compute.manager [instance: 90c79adf-4df1-497c-a786-13bdc5cca98d]     *args, **kwargs)
2014-06-24 22:54:52.973 16186 TRACE nova.compute.manager [instance: 90c79adf-4df1-497c-a786-13bdc5cca98d]   File "/opt/stack/new/nova/nova/compute/manager.py", line 2788, in snapshot_instance
2014-06-24 22:54:52.973 16186 TRACE nova.compute.manager [instance: 90c79adf-4df1-497c-a786-13bdc5cca98d]     task_states.IMAGE_SNAPSHOT)
2014-06-24 22:54:52.973 16186 TRACE nova.compute.manager [instance: 90c79adf-4df1-497c-a786-13bdc5cca98d]   File "/opt/stack/new/nova/nova/compute/manager.py", line 2819, in _snapshot_instance
2014-06-24 22:54:52.973 16186 TRACE nova.compute.manager [instance: 90c79adf-4df1-497c-a786-13bdc5cca98d]     update_task_state)
2014-06-24 22:54:52.973 16186 TRACE nova.compute.manager [instance: 90c79adf-4df1-497c-a786-13bdc5cca98d]   File "/opt/stack/new/nova/nova/virt/libvirt/driver.py", line 1532, in snapshot
2014-06-24 22:54:52.973 16186 TRACE nova.compute.manager [instance: 90c79adf-4df1-497c-a786-13bdc5cca98d]     image_format)
2014-06-24 22:54:52.973 16186 TRACE nova.compute.manager [instance: 90c79adf-4df1-497c-a786-13bdc5cca98d]   File "/opt/stack/new/nova/nova/virt/libvirt/driver.py", line 1631, in _live_snapshot
2014-06-24 22:54:52.973 16186 TRACE nova.compute.manager [instance: 90c79adf-4df1-497c-a786-13bdc5cca98d]     domain.blockJobAbort(disk_path, 0)
2014-06-24 22:54:52.973 16186 TRACE nova.compute.manager [instance: 90c79adf-4df1-497c-a786-13bdc5cca98d]   File "/usr/lib/python2.7/dist-packages/eventlet/tpool.py", line 179, in doit
2014-06-24 22:54:52.973 16186 TRACE nova.compute.manager [instance: 90c79adf-4df1-497c-a786-13bdc5cca98d]     result = proxy_call(self._autowrap, f, *args, **kwargs)
2014-06-24 22:54:52.973 16186 TRACE nova.compute.manager [instance: 90c79adf-4df1-497c-a786-13bdc5cca98d]   File "/usr/lib/python2.7/dist-packages/eventlet/tpool.py", line 139, in proxy_call
2014-06-24 22:54:52.973 16186 TRACE nova.compute.manager [instance: 90c79adf-4df1-497c-a786-13bdc5cca98d]     rv = execute(f,*args,**kwargs)
2014-06-24 22:54:52.973 16186 TRACE nova.compute.manager [instance: 90c79adf-4df1-497c-a786-13bdc5cca98d]   File "/usr/lib/python2.7/dist-packages/eventlet/tpool.py", line 77, in tworker
2014-06-24 22:54:52.973 16186 TRACE nova.compute.manager [instance: 90c79adf-4df1-497c-a786-13bdc5cca98d]     rv = meth(*args,**kwargs)
2014-06-24 22:54:52.973 16186 TRACE nova.compute.manager [instance: 90c79adf-4df1-497c-a786-13bdc5cca98d]   File "/usr/lib/python2.7/dist-packages/libvirt.py", line 646, in blockJobAbort
2014-06-24 22:54:52.973 16186 TRACE nova.compute.manager [instance: 90c79adf-4df1-497c-a786-13bdc5cca98d]     if ret == -1: raise libvirtError ('virDomainBlockJobAbort() failed', dom=self)
2014-06-24 22:54:52.973 16186 TRACE nova.compute.manager [instance: 90c79adf-4df1-497c-a786-13bdc5cca98d] libvirtError: Unable to read from monitor: Connection reset by peer
2014-06-24 22:54:52.973 16186 TRACE nova.compute.manager [instance: 90c79adf-4df1-497c-a786-13bdc5cca98d]