subject: Openvz Vs. Xen [print this page] Xen is the platform of choice for heavy duty, production-grade virtualized deployments, while OpenVZ is optimum for lightweight uses, explains Solar VPS founder and COO Ross Brouse. While I would choose Xen nine times out of 10, I know that OpenVZ is a great platform for applications such as DNS and VPN, as well as SEO optimization, static websites and project-based work.
XenWith Xen, he says, you run your own instance of the Linux kernel; you have virtualized memory, IO and scheduler; and its generally uninterrupted performance.
OpenVZOpenVZ, on the other hand, is an OS-level virtualization system that runs as a thin layer on top of the host OS, providing great speed and ease of support for service providers. Theyre both excellent virtualization platforms that weve selected for top performance. OpenVZ tends to be more attractive to Web developers because it does exactly what they need it to do at an affordable cost.
Overview
Xen is an open source technology, delivering support for a range of operating systems including Windows and Linux. The Xen hypervisor is a basic abstraction layer of software that sits directly on the hardware below any operating system. It is responsible for CPU-scheduling and memory-partitioning of the various VMs running on the hardware.
Xen supports running two different methods of virtualization: PV and HVM. Both can be used at the same time on a single Xen system. PV (or aparavirtualization) is an efficient virtualization method that doesnt require virtual extensions from the host. XenPV was designed for running various versions of the Linux OS including RedHat (CentOS), Debian, Fedora, SUSE and Gentoo; though each unique OS must be ported.
XenHVM (Hardware Virtual Machine fully virtualized) requires CPU virtualization extensions from the host (Intel VT, AMD-V). XenHVM is kernel-agnostic and thus supports Windows.
OpenVZ is an open source, software-based virtualization platform built on the Linux kernel and OS (ergo it does not apply to Windows users). It creates isolated, secure environments on a single physical host, allowing for separation of resources and security between those environments. Each partitioned server performs and executes exactly like a stand-alone server: can be rebooted independently and has unique root access, users, IP addresses, memory, processes, files, applications, system libraries and configurations.
Choice Analysis
The Xen platform is more diversified than OpenVZ, meaning it supports a wider range of operating systems. Xen also better emulates a true server environment as its hypervisor-based architecture provides a customizable hardware layer within the guest system. This provides exceptional control of the hardware and software layers for the end-user.
While Xen is a popular choice among IT mavens, many hosted service providers will tell you OpenVZ is a better fit due to its speed and low price point. OpenVZ also provides an extremely agile and expandable hosting environment due to its software-based nature and its ability to share critical system libraries and processes.
In the end, if youre choosing a VPS platform, you want to feel as if youre getting a dedicated server for the price of a shared server, explains Brouse. Weve opted for Xen in past because, after surveying our clients and finding they want the hypervisor setup for business and for Windows, we knew we could rely on Xen implicitly.
Weve developed a custom provisioning and management setup at Solar, Brouse continues. Were now on the verge of offering OpenVZ to our developer clients using Linux in order to offer them the greatest bang for their buck.
Ultimately, each platform offers different advantages. In other words, when you consider the big picture, one isnt really better than the other. Theyre different; and each is useful to a population of its own. While Xen reigns supreme in terms of stability, OpenVZ offers speed and price flexibility. You win with either, and thats why well offer both, Brouse says. Weve chosen to offer both technologies for the impending launch of our new Solar System automation platform.
