Xen™ 3.1 is launched bringing a 64-bit hypervisor, live relocation and XenAPI

Xen™ 3.1 is launched bringing a 64-bit hypervisor, live relocation and XenAPI

Summary: The good folks at XenSource announced Xen™ 3.1 today.


The good folks at XenSource announced Xen™ 3.1 today. This release is a wonderful demontration of a community effort. The list of contributors to Xen 3.1 include XenSource itself, Intel, IBM, Novell, VA Linux (Japan), HP, Fujitsu, SGI, Red Hat, AMD, Sun, Unisys and the U.S. National Security Agency. Impressive list, no? Here's a capsule description of what's new.

  • Enhanced 64 bit hypervisor – Xen 3.1 extends Xen’s paravirtualization support to allow simultaneous virtualization of both 32- and 64-bit paravirtualized Linux virtual machines. This improvement adds to what earlier versions of Xen already offered including, support for 32 and 64 bit hardware assisted virtual machines (HVM). Xen 3.1 is able to simultaneously virtualize todays 32 bit Linux and Windows guests as well as important 64 bit enterprise workloads such as Microsoft® Exchange Server, SQL Server 2007, Oracle, DB2 and SAP. The new 64 bit hypervisor can utilize very large memory configurations to permit virtualization of memory intensive applications such as database engines while offering good levels of performance. This hypervisor would certainly increase the number and type of virtual machines that could be hosted on a single server. Since Xen 3.1 also offers parvirtualized I/O and support for up to 32 physical CPUs, it is likely that industry observers will note that this is the most scalable hypervisor available. XenSource also points out that Xen 3.1 also includes pre-silicon support for AMD enhanced page table management.

  • Live relocation – Xen 3.1 supports Intel® Virtualization Technology (Intel® VT) or AMD® Virtualization (AMD-V) hardware-assisted virtualization to offer live relocation and dynamic memory control. This support is likely to really improve responsiveness of virtual systems by enabling dynamic resource scheduling and “no-downtime maintenance” of Microsoft® Windows® based virtual environments.

  • XenAPI – Xen 3.1 is also offering a management API which should kick the Xen ISV ecosystem into high gear. XenSource is also offering an XML-RPC based management API that supports the Xen project's implementation of the evolving DMTF standard for virtualization management.

When I posted XenSource: a virtual unknown back in late April, I mentioned that

"Even though Xen, virtual machine software for industry standard systems, is well known, The company behind this software, XenSource, is not as well known.

After I published that post, I received numerous messages from virtualization fans all over the Internet. Many of these messages expressed surprise that XenSource was behind Xen. I believe announcements such as this one will help educate the market about XenSource and the community behind Xen. I applaud XenSource and its partners for what they're doing for the community and the industry as a whole.

By the way, they didn't mention Green Computing in their press release. I think they missed a really important feature of this software. Organizations will be able to assign more work to a single machine. This, potentially, could reduce the number of machines, the amount of power consumed and the amount of heat produced by an organization's workload.

Is your organization likely to test this software? What would the key criteria be for your organization to adopt this software?

Topics: Processors, Hardware, Virtualization


Daniel Kusnetzky, a reformed software engineer and product manager, founded Kusnetzky Group LLC in 2006. He's literally written the book on virtualization and often comments on cloud computing, mobility and systems software. In his spare time, he's also the managing partner of Lux Sonus LLC, an investment firm.

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  • How well does it do Windows?

    With Longhorn Server's virtual capability being pushed off to some time after get their own stuff working, running Windows servers on Xen would be nice. Does running Windows on Xen efficiently and reliably require support that's not currently built into Windows?
    • XenSource says it supports windows

      The XenSource press release includes the following text.

      this enables Xen 3.1 to simultaneously virtualize legacy 32 bit Linux and Windows guests, and key 64-bit enterprise workloads, such as Microsoft Exchange Server, SQL Server 2007, Oracle, DB2 and SAP.
      <end snip>

      Unless they're fibbing, Windows software can run in a Xen environment.
      • Last I knew, it still required a HVM processor.

        Otherwise, you can only do "Para-Virtualization," which requires a kernel that's aware of the Xen environment. To date, no Windows kernel has been publicly released (though a private XP kernel was created just to prove it can work).

        Many modern processors built for the machine room are capable of running Windows under Xen, but you aren't likely to find this capability on many desktops.

        If you need a freeware virtualization solution capable of running Windows in a VM on a desktop or other non HSV processor, may I suggest Innotek's VirtualBox? It's not nearly as efficient as Xen, but it does do a very impressive job. Only really useful for Win2K and later on the MS client side (Win9x will be stuck w/ 16 colors).