VM Build Fails as Network Fails to Get due to Allocated

Problem

The VM build is failing due to the network not being allocated, although the network agents remain running and in a healthy state.

Server show and logs

//Server show
{u'message': u'Build of instance [VM_UUID] aborted: Failed to allocate the network(s), not rescheduling.', u'code': 500,..raise exception.VirtualInterfaceCreateException()<br>ova.exception.VirtualInterfaceCreateException: Virtual Interface creation failed<br>During handling of the above exception, another exception occurred}

//ostackhost logs
nova.exception.VirtualInterfaceCreateException: Virtual Interface creation failed
eventlet.timeout.Timeout: 300 seconds

Environment

• Platform9 Managed OpenStack - v4.0 and Higher

Cause

The VM creation failed because Nova did not receive the network-vif-plugged event within the expected timeout, resulting in a VirtualInterfaceCreateException. Although the instance was scheduled successfully and network agents appeared healthy, the event was not delivered to Nova due to a communication issue between Neutron and Nova. As a result, the port binding was never confirmed, and Nova aborted the build with the error “Failed to allocate the network(s), not rescheduling.”

This is a known bug and is reported internally with ID: IAAS-10813.

Resolution

The services given below need to be restarted to fix the issue. Ensure all services are up and running. Once services are stable, attempt to build the new instance.

command

$ systemctl restart openvswitch
$ systemctl restart pf9-neutron-ovs-agent
$ systemctl restart systemd-machined

In case this does not help please reach out to the Platform9 support team to restart the neutron-server service on the DU.

command

$ systemctl restart neutron-server

Additional Information

For further questions/concerns regarding the bug, reach out to the Platform9 Support Team