CPU spikes to 100% site doesn’t load, VPS crashes after moving site

First of all try to disable access to your site for all but you in .htaccess file:

deny from all
allow from

where is your current IP. If your site is crashing the VPS even then, this means that you have an epic misconfiguration of the VPS. Having a closer look at the resource-greedy processes using the console command top (or installing htop, which is better) would give you some more hints on the case.

If your site works well just for you after you’ve limited access to others, it’s time to see what’s wrong with it – profiling, fine-tuning of your web-server (apache or other), your MySQL, caching and so on.

I had a funny case of an anti-virus and anti-spam daemons slowing page-load with more than 10 seconds without having any load on the site… so stay open minded for stuff like this!