We have an issue after migrating to the OVN-Kubernetes network with OpenShift on OpenStack - OCPBUGS-16910.

The minimal requirements of the worker nodes in openstack are 2 vCPUs and 8 GB RAM. [0] [1]

Increased the flavor size to match the master nodes requirements: 4 vCPUs and 16 GB RAM, and the issue didn't reproduce - the worker nodes are not overloaded during the conformance tests anymore. [2] 

Discussed in a Slack thread, and decided we might state in the docs that it is recommended to use the flavor that matches the master nodes when migrating to the OVN-Kubernetes network. [3] 

 
We have a similar statement in https://github.com/shiftstack/installer/blob/master/docs/user/openstack/README.md#worker-nodes:

However, if you are experiencing Out Of Memory issues, or your installs are timing out, try increasing the size of your flavor to match the master nodes: 4 vCPUs and 16 GB RAM.

Note that using the workers minimal requirements, all the functionality works, but the workers can get overloaded when running many tests in parallel.

[0] https://github.com/shiftstack/installer/blob/master/docs/user/openstack/README.md#worker-nodes
[1] https://docs.openshift.com/container-platform/4.13/installing/installing_openstack/installing-openstack-installer-custom.html#installation-osp-compute-machines_installing-openstack-installer-custom
[2] https://issues.redhat.com/browse/OCPBUGS-16910?focusedId=22871729&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-22871729 
[3] https://redhat-internal.slack.com/archives/CH98TDJUD/p1693205778786629