[gmuslera]

I would use Telegraf (a better/distributed collector far more efficient than cacti, even if you have to learn the OIDs for the snmp devices you want to monitor, because not everything is snmp anyway), InfluxDB (a timeseries database better than rrd, is not the only alternative, but at least it works for me), and yes, Grafana.

The cron gives you low granularity (and for some things, it may matter to measure things that changes in less than a minute), and flexibility (both in what you can measure and how you can arrange and correlate the different pieces of information).