I have a complex web application running on a Debian/Nginx/PHP5-FPM stack. The application usually has ~600 online users everytime, and ~5000 unique users per-day.
The stack is running on a Xen-based VM with 2 dedicated cores (Intel Xeon E5420) and 2GB of RAM.
I see that PHP5-FPM uses a lot of CPU, usually 10%-20% but sometimes even 100% for some minutes. Average load (from uptime command) is "~1.5, ~2, ~2.5", but I've seen higher values (around 10).
I was wondering if the VM is powerful enought for running this app. And, more important, I was wondering if using Xen is actually a good choice or not (on the server there are two more VMs).
Thanks in advance!