Original URL: http://www.theregister.co.uk/2006/07/20/ms_xen_love/

Microsoft so very, very proud of its ties to open source Xen

VMware spat gets nasty

By Ashlee Vance

Posted in Servers, 20th July 2006 16:09 GMT

Analysis Few people outside of the server virtualization debate have encountered the mutual dislike that Microsoft and VMware have for each other. However, the spat between the two software makers has started edging closer to the general tech public due to events transpiring this week. And this is the kind of squabble that you want to start watching because both companies have abandoned subtle jibes in favor of blunt smacks to the face.

The move that really got things going was Microsoft's press release this week announcing a partnership with software maker XenSource. Given that Microsoft has referred to open source projects as "cancerous" in the past, it seemed rather odd for the company to take the trouble of issuing an entire statement celebrating a relationship with a rival that bases its whole business around the open source Xen package. We'd love to see a list of all the Microsoft press releases that have cheered an open source company in the past. Such a list can't be very long.

If Linux is full-blown cancer, then Xen has to be the equivalent of a colon polyp. The immature code has the potential to become a favorite among server administrators looking to carve up their systems into different partitions that can run both Windows and Linux - and even Solaris. Potential is the key word here since VMware has spent the last few years gobbling up the vast majority of the server virtualization market.

It doesn't take a Think Week to figure out that VMware's success triggered Microsoft's embrace of the Xen polyp. Microsoft has agreed to let Xen-wrapped Linux run on the upcoming version of its own server virtualization software due out in 2008 as an update to Longhorn Server. In addition, Microsoft will provide technical support for the Xen-infected Linux tumors growing out of its server OS.

Close observers will say there isn't much technological meat to this announcement. Who cares if Microsoft will run Xen-wrapped Linux guest operating systems? The fact is that Microsoft, VMware, XenSource and a host of other players will all be selling server virtualization products and hoping to win more than their fair share of the market. It's not like Microsoft is going to give XenSource a huge helping hand in the long-run.

The meat here comes from the publicity Microsoft has thrown XenSource's way. Microsoft's most unusual press release - with star EVP Craig Mundie in it no less - served to legitimize XenSource in the near-term and to rattle VMware.

Microsoft knows it can't compete with VMware in any real sense with its current Virtual Server product. It has to wait until 2008 for its fresh effort code-named Viridian to arrive. But if things continue as they have until 2008, the server virtualization market will be a lost cause for Microsoft.

With the mighty EMC behind it, VMware pulled in a whopping $157m during the second quarter on the back of 73 per cent year-over-year growth. We're talking about a $630m a year company with no signs of slowing down. VMware is looking a lot like the Microsoft of x86 server virtualization.

We're betting that Microsoft hopes XenSource can slow the VMware juggernaut, giving the coders in Redmond enough time to cram Viridian into Longhorn Server. Microsoft is betting that putting its name behind XenSource now will boost the start-up's near-term chances. And it would seem VMware knows what Microsoft is up to.

VMware this week started its own publicity war against Microsoft.

In a globule, VMware VP Brian Byun framed the Microsoft and Xen tie-up as he sees it. Here are a few highlights.

"It’s a one-way street that favors Microsoft and Windows running Linux. The arrangement will allow Linux to run on future Microsoft hypervisors through translated calls to the hypervisor when Windows is controlling the hardware, but not the other way around; i.e. there is no mention of Longhorn optimizations or 'enlightenments being ported to Xen or licensed to XenSource to enable a Xen hypervisor to run full optimizations with Longhorn OS."

"XenSource, in diverging from its open source and Linux virtualization roots, is enabling the commercial interests of Windows and building to proprietary Windows API layers. It stands to reason that in order to protect Windows from GPL contamination, XenSource will need to undertake a lot of non-GPL development to translate and buffer the Linux kernel from Windows hypervisor interfaces; and nothing that Microsoft licenses to, or develops with, XenSource is GPL and can be used directly by the Xen or Linux communities and commercial distributions."

"It’s odd to trumpet future interoperability for the Windows hypervisor whose first release is roughly two years away or more, while the Linux hypervisor interfaces are still being actively discussed in the open source community."

There's some rich history behind this Microsoft and VMware war of words and press releases.

Few took VMware seriously when it started out around the time of the dot-com boom. The software maker offered Unix-like partitioning on x86 servers, but everyone was buying Unix servers with glee back then. Why waste your time on an immature, low-end software package?

When the bust hit, VMware took off as a "server consolidation" miracle. To its credit, Microsoft became nervous in a hurry. It refused to support customers who ran Windows in a VMware virtual machine. It could see VMware starting to form basic, OS level relationships with customers.

Microsoft eventually caved on the support issue but didn't exactly embrace VMware as a rival/partner. Instead, Microsoft found it could not compete all that well against VMware with the Virtual Server product it acquired in the Connectix buy. So, it made Virtual Server free this year. On top of that, Microsoft announced that it will bundle "Viridian" with its operating system. Now, bundling a browser with a desktop operating system is one thing. Bundling a type of product that VMware sells for thousands of dollars per server is a much hairier beast - the kind of beast some judge or AG somewhere must be eyeing.

Lurking behind this nastiness is an element of the Microsoft and Xen relationship that we had forgotten about until a helpful reader sent in a reminder.

If you peek at this image, you'll see that a Microsoft researcher named Tim Harris once did quite a bit of work on the Xenoserver project, which turned into Cambridge University's Xen project. As it turns out, Microsoft gave Cambridge some funding for the Xen effort.

If you add this whole puzzle together, you realize that Microsoft got interested in virtualization long ago, primarily through the Xen research. Of course, Microsoft could never lower itself to pick up GPLed code. Instead, it decided to spend about five years hammering away on a Redmond clone of Xen.

Knowing that it can't compete in the market in the interim, Microsoft has played the old IBM trick of creating confusion. Don't go with VMware. Go with XenSource. That's who we like. Have a look at what they have to offer.

You can be sure that those niceties will end come 2008.

Until then, it's all open source press releases and love, love, love in Redmond - well, except for the VMware crowd. ®