Comment 26 for bug 1436414

Release notes:

Pacemaker can turn DHCP agent resource into unmanaged state in case of a large number of networks.
Pacemaker monitors DHCP agents on all controller nodes and restarts them if for some reason they are seemed to be dead.
By default Pacemaker will try to clean all artefacts created by the agent (namespaces, ports, processes). In case of a large number of
networks this procedure can take too long time to finish and the resource will be marked as unmanaged.
In such case the resources should be cleaned up by executing the following command: pcs resource cleanup p_neutron-dhcp-agent.

To prevent such cases cleanup on starting/stopping of Neutron DHCP agent resource can be disabled by executing the following command: pcs resource update p_neutron-dhcp-agent remove_artifacts_on_stop_start=true --force. Then disable and enable the resource to apply changes.

If resource need to be restarted without removing any artefacts (for example, to apply configuration changes or in other cases), it supports reload operation. It's required to change one of the resource parameters.
For example, execute pcs resource update p_neutron-dhcp-agent debug=true. The resource should be reloaded. If it's restarted instead of reloaded, try to change the parameter again, because Pacemaker may not start to accept changes from the very first try.