VM Creation Failed Due to Port Binding Failure

Problem

VM creation failed due to the following error:

ostackhost.logs

nova.exception.PortBindingFailed: Binding failed for port [PORT-UUID] please check neutron logs for more information.

Environment

• Private Cloud Director Virtualization - v2025.4 and Higher
• Private Cloud Director Kubernetes – v2025.4 and Higher
• Self-Hosted Private Cloud Director Virtualization - v2025.4 and Higher
• Self-Hosted Private Cloud Director Kubernetes - v2025.4 and Higher
• Component: Networking Service

Cause

This issue occurs when Neutron agents on compute nodes are unable to bind the requested port to the VM. Common causes include:

• OVN controller on the compute node is unresponsive or out of sync with the OVN Southbound database.
• Neutron server-to-OVN database communication issues.
• Stale port binding records in OVN or Neutron.

Diagnostics

• Review ostackhost logs on the affected compute host:

  $ cat /var/log/pf9/ostackhost.log | grep -i <VM_ID>

• Check Neutron agent status:

  $ openstack network agent list

• Review OVN controller logs on the compute node:

  $ sudo journalctl -u ovn-controller -f
  $ cat /var/log/ovn/ovn-controller.log

Resolution

Restart OVN services on the affected compute node(s):

$ sudo systemctl restart ovn-controller

Restarting ovn-controller on a compute node generally does not disrupt existing VM traffic since OVS flows remain programmed, but it temporarily prevents new port bindings, VM spawns, or security group updates

Validation

• Confirm the VM builds successfully
• Verify the Neutron port binding:

  $ openstack port list --server <vm-id>