SR-IOV guide for OVN

The purpose of this page is to describe how SR-IOV works with OVN. Prior to reading this document, it is recommended to first read the basic guide for SR-IOV.

External ports

The SR-IOV feature is leverage by OVN external ports. For more information about external ports, its scheduling and troubleshoot, please check the External Ports guide.

Environment setup for OVN SR-IOV

There are a very few differences between setting up an environment for SR-IOV for the OVS and OVN Neutron drivers. As mentioned at the beginning of this document, the instructions from the the basic guide for SR-IOV are required for getting SR-IOV working with the OVN driver.

The only differences required for an OVN deployment are:

  • When configuring the mechanism_drivers in the ml2_conf.ini file we should specify ovn driver instead of the openvswitch driver

  • Disabling the Neutron DHCP agent

  • Deploying the OVN Metadata agent on the gateway nodes (controller or networker nodes)

Known limitations

The current SR-IOV implementation for the OVN Neutron driver has a few known limitations that should be addressed in the future:

  1. Routing on VLAN tenant network will not work with SR-IOV. This is because the external ports are not being co-located with the logical router’s gateway ports, for more information take a look at bug #1875852.