I'm developing a website. I was wondering if there are any tools out there that make it easy to log and graph usage statistics of how my cpu, memory, disk and network are used.

I need to somehow know when I need to scale up / when I'm going to get problems soon.

I found <http://sebastien.godard.pagesperso-orange.fr/>
(command line thingy, not so useful because I'd have to write my own graphics and logging layer on top of it..)