Generally speaking, you can't compare OpenVZ to XEN/KVM since those are completely two different worlds.
OpenVZ: Linux only, (very) shared resources which makes it harder to avoid from one VM cause trouble to others (resources / performance wise).
XEN/KVM: Better performance, better isolation features between each and every VM (H/W resources wise), supports both Windows and Linux OS.
In short, if you are going to offer Linux and Windows VMs, certainly OpenVZ is a no go, you have to choose either KVM Or XEN and here, it's up to each individual's taste. Google for both and find which one you find more suitable for your taste.
Generally speaking VMs running on KVM vs XEN benchmark better in solusvm. I tested both before deciding which to use in our solusvm system. Make sure your use virtio drivers for any windows VMs/templates too if you choose KVM. Also solusvm didnt support the latest XEN at the time of our install, so that was another reason. Xen has a few different VM levels , PV & HVM too. It all depends on the control panel you plan to go with to manage your vms or resell them.
We have moved almost everything to VMware. However, we still have some infrastructure for KVM-based VM's and we like it more than Xen... which does't mean that Xen itself isn't a very good virtualization technology.
As already said it depends on your needs but also on your knowledge. If you don't feel comfortable to admin kvm or xen don't go that route. You need to work with it every day and in case of problems needs to be able to solve this issues quick!
Linux KVM VPS is an ideal bridge between shared hosting and dedicated servers. With full root access, you're able to install advanced software and completely customize it easily.
Whenever you need to add or remove a module from your Linux kernel, you can easily do that!
This can be decided based on the application that you are going to run on your vps. Please let us know about the application that you are planning to run on vps so that we can provide correct information
it depends on what your goals are, xen performance for large enterprise servers is better than KVM (or was some time ago). KVM seems to work better in a bundled solution such as Solusvm. so like so many things ... it depends.
determine your hardware, what you plan to use it for, control panels, etc and advantage and disadvantages in KVM and XEN and then make a decision and go for it
We recommend Xen virtualization because it is fully virtualization and works on systems that support virtualization extensions, but can also work as a hypervisor on machines that don't have the virtualization extensions. Xen is a hypervisor that supports x86, x86_64, Itanium, and ARM architectures, and can run Linux, Windows, Solaris, and freeBSD.
SolumVM or XenCenter(Citrix) panels are used to manage Xen.
Well, KVM is better for me. It is a full virtualization solution for Linux on x86 hardware containing virtualization extensions (Intel VT or AMD-V). It consists of a loadable kernel module, kvm.ko, that provides the core virtualization infrastructure and a processor specific module, kvm-intel.ko or kvm-amd.ko.
Xen virtualization is a technology that allows multiple operating systems to run on a single computer. It can be helpful if you want to run different versions of Windows or to use a Linux distribution on your computer but don't have the space for it. Xen also allows you to run multiple applications simultaneously on a single machine. It is helpful if you need to perform multiple tasks simultaneously or use different applications for different tasks.
The Xen hypervisor uses a micro-kernel design that runs on bare-metal hardware and can run on systems without virtualization extensions. In addition, Xen has various new security features, including Linux stub domains, a lightweight VM fork to analyze malware, and a live patch feature with higher granular control over patching & support for the hardware-based Control-flow Enforcement Technology Shadow Stack.
KVM is an abbreviation for Kernel-based Virtual Machine, a virtualization technology built into the standard Linux Kernel. It allows you to run the kernel on the root node, making it possible to run other operating systems. KVM requires the hardware to run its own virtualization extensions, but this should not cause a problem, given that most non-Atom Intel and AMD processors come with these extensions.
KVM VPS gives you complete liberation to set the values for your resources based on the requirements of your application. Moreover, it provides virtualization of only the existing system's hardware resources. So, all the shared resources, such as disk space, CPU time, and network IO will be fairly distributed by the hypervisor.
Benefits of XEN Virtualization for VPS server:
Increases the flexibility of a server
Improve the performance of VPS
More efficient server
Stability of server
Benefits of KVM Virtualization for VPS server:
Reduces the amount of hardware required for server
Decreases the maintenance costs
I hope the above information helps you to understand which virtualization is the best, XEN or KVM, for the VPS server.