“In this howto I will describe how to prepare a CentOS 4.4 server for OpenVZ virtual machines. With OpenVZ you can create multiple Virtual Private Servers on the same hardware, similar to Xen and the Linux Vserver project. OpenVZ is the open-source branch of Virtuozzo, a commercial virtualization solution used by many providers that offer virtual servers.”
But I’d like to say it for those who do not know yet:
If you need to virtualize your host kernel (allow many instances of this kernel to run on the same machine) OpenVZ is for you! For weeks, I have been trying UML, Xen, Vmware, Vserver, while the others took me more than one day to setup (expect Vmware) I was running my first virtual machine in less than one hour with OpenVZ! It’s easy to configure, easy to maintain, IMHO it’s the most “Enterprise Ready” solution to date. Don’t look back: go try it!
P.S. Of course you cannot do everything with OpenVZ, as it provides only environment virtualization, but in most cases that will be enough.
It isn’t for everybody promotion-aside. Since every OpenVZ guest shares the same kernel as the host this rules out a lot of obvious use.
Personally I much prefer Xen. It might not be the best for everybody, but it certainly meets my needs, and when it doesn’t there are other options to experiment with VMWare, Qemu, Parallels, etc.
There isn’t one globaly solution for everybody, people should investigate the available solutions and choose which one makes the most sense for their scenario.
(FWIW I found UML, Xen, and OpenVZ each equally simple to setup .. but maybe you were just confused/lucky.)