OpenVZ vs Xen, how much difference in performance?

Question

There is a Xen vs. KVM in performance question on ServerFault.

What will be the speed difference if the choice is between Xen and OpenVZ?

Searching for such benchmarks does not show any results newer than 2008.

What would be some important performance measurements to compare OpenVZ against Xen?

Some may say "you're comparing oranges and pineapples" but I have to choose 1 of the 2 and it needs to be a wise choice. Performance is most important to us. We may switch away from OpenVZ because Xen is more ubiquitous but only if performance overhead is not significant. Next month (January 2011) I'm thinking of doing my own performance comparison - here is the project planning blog.

Answer 1

If you were only running linux, then openvz might serve quite well. I like to think of it as a super-chroot environment.

I also find it easier to tweak openvz vs Xen, as well as ability to see some unexpected memory consumption with certain apps, specifically exec in java.

I do have to admit that java apps can be a pita at times in openvz, but once tuned it works very well. I currently have 14 tomcat instances running on gentoo without any problem.

There is also a unique situation why I choose openvz and this is due to High Precision Event timing with some custom apps where Xen fails, so if you need very precise timing then Xen might fail you.

Answer 2

if you will have only linux as os into vms - then openvz is faster. look on google for benchmarks.

yes is not the same thing because openvz is a container and xen is a hypervisor.

however you should check on the progress of openvz because some linux distros dumped it.