Hmm, I tried what you said, but was not able to locate any data. When I go to the main ganglia server webui for HDPSlaves, there is only one host reporting in and it is the host running Ganglia server (reporting by dns name). I assume if there were others reporting in here by their ip address, I would see them listed here.
Everything is green in Ambari, gmond/gmetad are running on the Ganglia server host, and gmond is running on all other hosts, but none of them are reporting to the server. Maybe it is some kind of port issue.