Created attachment 320098 [details, diff] ovs-vswitchd.patch Openvswitch (ovs-vswitchd) requires ovsdb-server, so dependency should be need instead of use. Adding ovs-vswitchd to runlevel, but ovsdb-server not stops system startup because vswitchd is waiting for db.sock.
The database can also be on a remote server. So this is entirely at the admins discretion whether or not ovs-vswitchd requires ovsdb-server. This is expressed by using "use" instead of "need" such that the admin can add ovsdb-server to the runlevel himself.