Updating ovirt network used for OVN tunnel needs to be added to the docs.
Description below:

When a host is installed, it uses the "ovirtmgmt" network to set up
OVN tunnels (connecting the OVN hosts).
But, the user might want to use another network for this purpose.
This can be done by executing the "ovirt-provider-ovn-driver" ansible playbook
from the engine host, to change the configuation for all hosts in a cluster.
Steps:

1. Go to:
cd /usr/share/ovirt-engine/playbooks

2. Execute:
ansible-playbook --private-key=/etc/pki/ovirt-engine/keys/engine_id_rsa -i /usr/share/ovirt-engine-metrics/bin/ovirt-engine-hosts-ansible-inventory --extra-vars " cluster_name=<cluster name> ovn_central=<ovn central ip> ovn_tunneling_interface=<vdsm network name>" ovirt-provider-ovn-driver.yml

For example, for the following parameters:
  cluster: TEST_CLUSTER
  network: TEST_NETWORK
  ovn central ip: 192.168.0.1
the command will be:
ansible-playbook --private-key=/etc/pki/ovirt-engine/keys/engine_id_rsa -i /usr/share/ovirt-engine-metrics/bin/ovirt-engine-hosts-ansible-inventory --extra-vars " cluster_name=TEST_CLUSTER ovn_central=192.168.0.1 ovn_tunneling_interface=TEST_NETWORK" ovirt-provider-ovn-driver.yml

Note that "ovn_central" ip can, but does not have to be on the new network. The only requirement is that is has be reachable from all hosts.

Note that this only changes the settings on existing hosts. If new hosts are
added to the cluster, the procedure has to be repeated.


The OVN tunnel network can also be changed on an individual host by invoking:
vdsm-tool ovn-config <ovn central ip> <tunneling ip or network name>