We store the information in DB.
Usually detailed metrics data for 2 days and aggregate data (1 hour, 6 hours and 1 day).
You can fins the information in eam_measurement tables.
If the agent cannot communicate with the server it saves the information in /data dir.
Thanks for the reply. The information that I was looking for is the data that is stored when you edit a metric template (Administration->Monitoring Defaults->EDIT METRIC TEMPLATE).
You can find the information in eam_measurement_templ eam_monitorable_type tables