Hi, I see such problem from time to time. It's not consistently reproduceable. ====================== 2021-11-23 22:16:28.532 7 INFO nova.compute.manager [req-50817b01-e7ae-4991-94fe-e4c5672c481b - - - - -] [instance: 7021bf37-348d-4dfa-b0c5-6a251fceb6cd] During sync_power_state the instance has a pending task (spawning). Skip. 2021-11-23 22:21:28.342 7 WARNING nova.virt.libvirt.driver [req-814c98a4-3fd9-4607-9abb-5fbe5cef8650 3a4c320d64664d9cb6784b7ea52d618a 21384fe21ebb4339b1a5f2a8f9000ea3 - default default] [instance: 7021bf37-348d-4dfa-b0c5-6a251fceb6cd] Timeout waiting for [('network-vif-plugged', '735d97a3-db7c-42ed-b3be-1596d4cc7f4b')] for instance with vm_state building and task_state spawning.: eventlet.timeout.Timeout: 300 seconds ====================== The VIF/port is activated by OVN ovn-controller to ovn-sb. It seems that, either Neutron didn't capture the update or didn't send message back to nova-compute. Is there any known fix for this problem? Thanks! Tony