Comment 0 for bug 1708572

os：centos7.3
openstack：ocata

when I　tried to live-migrate　an instance，it is wrong:
2017-07-28 11:33:03.917 18473 ERROR oslo_messaging.rpc.server Traceback (most recent call last):
2017-07-28 11:33:03.917 18473 ERROR oslo_messaging.rpc.server File "/usr/lib/python2.7/site-packages/oslo_messaging/rpc/server.py", line 155, in _process_incoming
2017-07-28 11:33:03.917 18473 ERROR oslo_messaging.rpc.server res = self.dispatcher.dispatch(message)
2017-07-28 11:33:03.917 18473 ERROR oslo_messaging.rpc.server File "/usr/lib/python2.7/site-packages/oslo_messaging/rpc/dispatcher.py", line 222, in dispatch
2017-07-28 11:33:03.917 18473 ERROR oslo_messaging.rpc.server return self._do_dispatch(endpoint, method, ctxt, args)
2017-07-28 11:33:03.917 18473 ERROR oslo_messaging.rpc.server File "/usr/lib/python2.7/site-packages/oslo_messaging/rpc/dispatcher.py", line 192, in _do_dispatch
2017-07-28 11:33:03.917 18473 ERROR oslo_messaging.rpc.server result = func(ctxt, **new_args)
2017-07-28 11:33:03.917 18473 ERROR oslo_messaging.rpc.server File "/usr/lib/python2.7/site-packages/nova/exception_wrapper.py", line 75, in wrapped
2017-07-28 11:33:03.917 18473 ERROR oslo_messaging.rpc.server function_name, call_dict, binary)
2017-07-28 11:33:03.917 18473 ERROR oslo_messaging.rpc.server File "/usr/lib/python2.7/site-packages/oslo_utils/excutils.py", line 220, in __exit__
2017-07-28 11:33:03.917 18473 ERROR oslo_messaging.rpc.server self.force_reraise()
2017-07-28 11:33:03.917 18473 ERROR oslo_messaging.rpc.server File "/usr/lib/python2.7/site-packages/oslo_utils/excutils.py", line 196, in force_reraise
2017-07-28 11:33:03.917 18473 ERROR oslo_messaging.rpc.server six.reraise(self.type_, self.value, self.tb)
2017-07-28 11:33:03.917 18473 ERROR oslo_messaging.rpc.server File "/usr/lib/python2.7/site-packages/nova/exception_wrapper.py", line 66, in wrapped
2017-07-28 11:33:03.917 18473 ERROR oslo_messaging.rpc.server return f(self, context, *args, **kw)
2017-07-28 11:33:03.917 18473 ERROR oslo_messaging.rpc.server File "/usr/lib/python2.7/site-packages/nova/compute/utils.py", line 686, in decorated_function
2017-07-28 11:33:03.917 18473 ERROR oslo_messaging.rpc.server return function(self, context, *args, **kwargs)
2017-07-28 11:33:03.917 18473 ERROR oslo_messaging.rpc.server File "/usr/lib/python2.7/site-packages/nova/compute/manager.py", line 216, in decorated_function
2017-07-28 11:33:03.917 18473 ERROR oslo_messaging.rpc.server kwargs['instance'], e, sys.exc_info())
2017-07-28 11:33:03.917 18473 ERROR oslo_messaging.rpc.server File "/usr/lib/python2.7/site-packages/oslo_utils/excutils.py", line 220, in __exit__
2017-07-28 11:33:03.917 18473 ERROR oslo_messaging.rpc.server self.force_reraise()
2017-07-28 11:33:03.917 18473 ERROR oslo_messaging.rpc.server File "/usr/lib/python2.7/site-packages/oslo_utils/excutils.py", line 196, in force_reraise
2017-07-28 11:33:03.917 18473 ERROR oslo_messaging.rpc.server six.reraise(self.type_, self.value, self.tb)
2017-07-28 11:33:03.917 18473 ERROR oslo_messaging.rpc.server File "/usr/lib/python2.7/site-packages/nova/compute/manager.py", line 204, in decorated_function
2017-07-28 11:33:03.917 18473 ERROR oslo_messaging.rpc.server return function(self, context, *args, **kwargs)
2017-07-28 11:33:03.917 18473 ERROR oslo_messaging.rpc.server File "/usr/lib/python2.7/site-packages/nova/compute/manager.py", line 5281, in check_can_live_migrate_source
2017-07-28 11:33:03.917 18473 ERROR oslo_messaging.rpc.server block_device_info)
2017-07-28 11:33:03.917 18473 ERROR oslo_messaging.rpc.server File "/usr/lib/python2.7/site-packages/nova/virt/libvirt/driver.py", line 5750, in check_can_live_migrate_source
2017-07-28 11:33:03.917 18473 ERROR oslo_messaging.rpc.server block_device_info)
2017-07-28 11:33:03.917 18473 ERROR oslo_messaging.rpc.server File "/usr/lib/python2.7/site-packages/nova/virt/libvirt/driver.py", line 5874, in _assert_dest_node_has_enough_disk
2017-07-28 11:33:03.917 18473 ERROR oslo_messaging.rpc.server raise exception.MigrationPreCheckError(reason=reason)
2017-07-28 11:33:03.917 18473 ERROR oslo_messaging.rpc.server MigrationPreCheckError: Migration pre-check error: Unable to migrate e9411b18-ce84-4094-8811-ad9675c245f3: Disk of instance is too large(available on destination host:-458487758848 < need:21692416)
2017-07-28 11:33:03.917 18473 ERROR oslo_messaging.rpc.server.

I found the free space of the destination host is -458487758848(A negative number).
The same bug is in https://bugs.launchpad.net/mos/+bug/1650490
But I don't kwon how to update my nova.