Should I choose KVM or OpenVZ for my VPS?

Question

My VPS provider gives me the choice between KVM and OpenVZ. What is the best choice for a VPS with 128MB or 256MB RAM?

Answer 1

KVM has much better isolation than OpenVZ and in my experience KVM gets better performance as well. However I've heard some say they get better performance from OpenVZ. KVM has come a long way in the past year though, so I wouldn't be surprised if it's surpassed OpenVZ by now...

KVM also supports any operating system (in theory), whereas OpenVZ is limited to Linux only.

We're using KVM exclusively for our virtualization systems and have no interest in switching to anything else.

Answer 2

OpenVZ does not give your processes the full amount of allocated memory due to overhead, so for smaller memory VPSes, I would lean towards choosing KVM or XEN.

Answer 3

You may be curious in taking a look at our side by side KVM VPS vs OpenVZ/Virtuozzo vs Xen comparison.

Answer 4

Choose KVM because OpenVZ is often cheaper to others hosts :)