Question, vnstat but for RAM or CPU usage?

[profesionalaiesam]

Hey, love the tool!

I wonder is there any alternative for tracking and saving data for RAM and CPU usage?

So I could use it like this?

[vergoh]

I had originally some ideas of including something like that in vnStat but rather fast realized that is would be more like feature creep and it wouldn't even fit well with the existing outputs anyway. The issue you get when trying to represent RAM and CPU usage is that those aren't counters but instead gauges. As a result, you wouldn't be able to show the daily usage in the same way you have in that screenshot as most likely the minimum / average / maximum CPU/RAM isn't that useful of information on a daily level. It works better if you have a graph which shows how the CPU/RAM usage varies over day/months.

Assuming a graphical representation is an option, with rrdtool you can rather easily get something like these created:

Or if you want something more interactive then I'd suggest looking at for example Grafana + InfluxDB, but those will obviously require far more resources to have running than rrdtool in comparison. Possibly there may also be tools targetting only this sort of monitoring but I haven't been searching for such so I don't know what the current alternatives would be.