Hi,
We are considering a transition from OpenVZ to Xen for our web server infrastructure. The primary task performed by the virtual servers is to run a number of Drupal sites with a MySQL backend. The webserver and MySQL servers are on separate virtual hosts. We also have a number of smaller hosts running on the same hardware (a couple of dev-servers, a logging-and-monitoring server, a secondary webserver ++).
From what I have understood, there is very little performance degradation in
OpenVZ, also for IO operations, due to the use of isolated containers instead of actual virtualisation. I have also seen tests indicating detrimental IO performance of Xen IO [1]. Despite this, I have found several posters [2] suggesting the use of Xen over OpenVZ when it comes to running Drupal sites.
One of the main arguments against OpenVZ is unpredictable and variable performance because VPS-hosts tend to overbook their host capacitiy. This is not an issue for us since we host our own VPSs on our own hardware so we are in complete control.
So: Is there any reason Xen may be able to outperform OpenVZ for the webserver-setup I have described, or should I just continue to use OpenVZ?
Cheers, Einar
Sources: [1] http://www.ilsistemista.net/index.php/virtualization/1-virtual-machines-perf... [2] http://2bits.com/articles/hosting-virtualization-openvz-vs-xen-which-is-best...