November 28, 2008 - Matthijs Haverink

The Power of XEN

Last week I attended a meeting with several guys from Citrix. Purpose of the meeting was to convince us that the latest releases of Citrix XenServer are mature products for the enterprise market. Why this meeting? Because lot’s is said about Xen (the non commercial product) and XenServer (Citrix commercial product), but for now it only has a 3% marketshare. So when customers ask us for a reference it far more difficult to give a reference than for example VmWare. But back to the point, What did Citrix tell us to convince us?

Well they first started to tell us about the non-commercial “engine” Xensource. This is of course is an open-source project which has been developped by the community for several years now. The biggest advantage of this way of deploping is that when for example one developper of the community needs a specific feature within the hypervisor, he will (try to) develop it and upload the new version to the community, this way a lot of people are working on a lot of different features. Disadvantage is of course that not all new features are 100% stable but close to it.

As we all know Citrix has aquired Xensource a year and a half ago, and developed a commercial product around the Xensource Hypervisor. But what did Citrix do to the product to be able to fully support the hypervisor? They tested, and tested, and tested and finally removed all unstable parts are redisgned certain parts to make it run Smoothly. This way they had all advantages from the open source development community and by the alliance with Microsoft they are able to make it perform for “Microsoft Windows” vritual machines aswell. They explained us that for this matter the non-commercial product still exists. New features are developed within the community, by Citrix itself, or even by Microsoft (because they use exactly the same hypervisor) . This way they can keep up with the evolution of the competition.

So a short summary:

Advantages XenSource:

– Quick Development

– Big Community (So even support is not that Bad)

– Almost native performance for Linux Clients

– Abbility to adjust

Additions XenServer

– Improved performance for Windows machines

– 100% stable product

– Full support on all features

By all means I’m convinced that XenServer is a enterprise ready product which is build on a solid piece of technology.

Virtual Infrastructure Citrix / xen / xenserver / xensource /


  • Patrick says:

    Hi Wouter,

    nice read but do have some small comments…
    Citrix has indeed acquired XenSource. XenSource was one of the commercial implementations of the Xen project.

    Xen is opensource
    XenServer uses Xen hypervisor

    So the “engine” as you refer to is Xen ( where Citrix (formally XenSource) XenServer is one of the enterprise implementations.

    But good to hear you do see future in the Citrix XenServer product.

    As a shameless plug I also would like to point you to PlateSpin as we provide consolidation planning and migrations onto the XenServer Enterprise platform.. 🙂


  • Duncan says:

    and it’s VMware instead of VmWare 🙂

    and although the development of Xen, the hypervisor, is quick… it doesn’t mean that the implementation of this hypervisor is also quick or the development of the management tools to address these new features for that matter.

    If you’ve got some spare time take a look at Virtual Iron. They also use the Xen hypervisor and have a good pricing scheme, and do pxe boot which is really cool in my opinion.

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