Comment 1 for bug 1586065

According to nova-compute logs:
2016-05-20 13:38:07.213 28838 ERROR oslo.service.loopingcall Traceback (most recent call last):
2016-05-20 13:38:07.213 28838 ERROR oslo.service.loopingcall File "/usr/lib/python2.7/site-packages/oslo_service/loopingcall.py", line 136, in _run_loop
2016-05-20 13:38:07.213 28838 ERROR oslo.service.loopingcall result = func(*self.args, **self.kw)
2016-05-20 13:38:07.213 28838 ERROR oslo.service.loopingcall File "/usr/lib/python2.7/site-packages/oslo_service/loopingcall.py", line 377, in _func
2016-05-20 13:38:07.213 28838 ERROR oslo.service.loopingcall return self._sleep_time
2016-05-20 13:38:07.213 28838 ERROR oslo.service.loopingcall File "/usr/lib/python2.7/site-packages/oslo_utils/excutils.py", line 220, in __exit__
2016-05-20 13:38:07.213 28838 ERROR oslo.service.loopingcall self.force_reraise()
2016-05-20 13:38:07.213 28838 ERROR oslo.service.loopingcall File "/usr/lib/python2.7/site-packages/oslo_utils/excutils.py", line 196, in force_reraise
2016-05-20 13:38:07.213 28838 ERROR oslo.service.loopingcall six.reraise(self.type_, self.value, self.tb)
2016-05-20 13:38:07.213 28838 ERROR oslo.service.loopingcall File "/usr/lib/python2.7/site-packages/oslo_service/loopingcall.py", line 356, in _func
2016-05-20 13:38:07.213 28838 ERROR oslo.service.loopingcall result = f(*args, **kwargs)
2016-05-20 13:38:07.213 28838 ERROR oslo.service.loopingcall File "/usr/lib/python2.7/site-packages/nova/virt/libvirt/guest.py", line 342, in _do_wait_and_retry_detach
2016-05-20 13:38:07.213 28838 ERROR oslo.service.loopingcall reason=reason)
2016-05-20 13:38:07.213 28838 ERROR oslo.service.loopingcall DeviceDetachFailed: Device detach failed for vdb: Unable to detach from guest transient domain.)

It looks like a nova issue