After the installation collectd is not running. To start collectd, use start.
You will get a feedback about the status.
* Caching service dependencies [ ok ] * Starting lighttpd... [ ok ]
If you want to stop the server use stop.
After changing the configuration file collectd needs to be restarted.
Normally you want to start the collectd server when the system is launching. This is done by adding collectd to the needed runlevel.