portal activity report: aggregator

In order to gather data for the portal activity report an aggregator process has to be active. We can start the aggregator at the command line, but then the shell window has to stay open all the time.

Is there a way to let this process run on the background?

Does anyone has some practical tips for the aggregator parameters? Do we have to set them to a specific value or are the default values OK?

Regards,

Johan