The rabbitmqctl restart_vhost command can be used to restart a virtual hosts. In this example, the "foo" virtual host is restarted. If the virtual host is already running, something like this should be returned.
~]# rabbitmqctl restart_vhost --vhost foo
Trying to restart vhost 'foo' on node 'rabbit@server001' ...
Vhost 'foo' is already running on node 'rabbit@server001'