I rent a dedicated server for one of my sites (Linux, WHM/cPanel). The site gets a decent number of monthly visitors (over a million), and I am starting to wonder how I should monitor it to discover when a server upgrade will be needed.
Obviously I could wait until the server starts to crash a lot and the site starts loading very slowly, but I would like to avoid reaching that point, having a better way to monitor things.
My questions:
1. Is monitoring the server load on WHM enough to know whether or not an upgrade is needed? On my case average server load is 0.5, and the server has 8 cores, so is this enough to say I probably don't need an upgrade?
2. Is there some other metric I should pay attention to to evaluate this?
Thanks in advance.