[Openstack-operators] attaching network cards to VMs taking a very long time

Matt Riedemann mriedemos at gmail.com
Wed May 16 21:09:42 UTC 2018

On 5/16/2018 10:30 AM, Radu Popescu | eMAG, Technology wrote:
> but I can see nova attaching the interface after a huge amount of time.

What specifically are you looking for in the logs when you see this?

Are you passing pre-created ports to attach to nova or are you passing a 
network ID so nova will create the port for you during the attach call?

This is where the ComputeManager calls the driver to plug the vif on the 


Assuming you're using the libvirt driver, the host vif plug happens here:


And the guest is updated here:


vif_plugging_is_fatal and vif_plugging_timeout don't come into play here 
because we're attaching an interface to an existing server - or are you 
talking about during the initial creation of the guest, i.e. this code 
in the driver?


Are you seeing this in the logs for the given port?


If not, it could mean that neutron-server never send the event to nova, 
so nova-compute timed out waiting for the vif plug callback event to 
tell us that the port is ready and the server can be changed to ACTIVE 

The neutron-server logs should log when external events are being sent 
to nova for the given port, you probably need to trace the requests and 
compare the nova-compute and neutron logs for a given server create request.




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