I recently setup Kamon, Statsd, Graphite, Grafana to monitor my akka application. I used the Docker container for Statsd, Graphite and Grafana that most tutorials suggest and it all worked fine until recently when I noticed the Grafana dashboard was starting to lag and become unresponsive. 
Its now become unresponsive and the reason is the machine hosting the Docker container has run out of space...

```
85790556    /var/lib/docker
85786096    /var/lib/docker/aufs
42922104    /var/lib/docker/aufs/diff
42863828    /var/lib/docker/aufs/mnt
42863668    /var/lib/docker/aufs/mnt/1daed028a6ca7041dc95257b27328324936f548d2cfc589d6e3c94ac3d8cc63b
41878192    /var/lib/docker/aufs/mnt/1daed028a6ca7041dc95257b27328324936f548d2cfc589d6e3c94ac3d8cc63b/opt
41793244    /var/lib/docker/aufs/diff/1daed028a6ca7041dc95257b27328324936f548d2cfc589d6e3c94ac3d8cc63b
41754416    /var/lib/docker/aufs/mnt/1daed028a6ca7041dc95257b27328324936f548d2cfc589d6e3c94ac3d8cc63b/opt/graphite

```

This is likely from the monitoring stats building up.
So I've two questions...

1. How do I safely clean up space in this container to get it running again.
2. Can I configure statsd or graphite to periodically purge data?

Thanks!