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How Virtualization Led Microsoft to Support Linux
Carl Bialik from WSJ writes "Why did Microsoft make the surprise announcement that it would support business customers who also use Linux? Because of the increasing importance of virtualization, Lee Gomes writes in the Wall Street Journal. 'Once businesses start using virtualization to cut back on the number of machines they need to buy, "a light bulb goes on over their head," says Tony Iams, who follows the field for Ideas International, an analyst group,' Gomes writes. 'Other uses become apparent, such as backing up data or easily adding processor power to a particular application as the need arises.' VMware pioneered the market, but now Microsoft is 'expected to offer sophisticated virtualization products in the next year or two,' Gomes writes. 'The company currently has a fairly rudimentary product, which was involved in its big Linux announcement earlier this month.'"
And wake me up when MS also natively supports Ext3, ReiserFS, etcetera on their own OSes too
Why? With virtualization, the host OS has no need to understand the guest OS's filesystem any more than it needs to know the guest's binary format. You just point it at a partition or an FS image file, and let it do its thing.
Some of us actually consider that one of the most useful features of running a virtual machine - Absolutely perfect 100% backups involve nothing more complicated than shutting down the guest OS and copying its image file. You can even perfectly backup a running OS that way, you just need to pause it and do a state dump; Then when you restart it, you resume right where you left off.
While I'm not part of the team, I do use VS on a regular basis and have a bit of insight on this topic.
First off, a little about how Linux support is accomplished. Virtual Server and Virtual PC use a package of "additions" which are installed in the "guest" virtual machine for performance and useability optimizations. The additions are basically device drivers optimized for for the virtualized hardware used inside the "guest". WIth luck and persistance, you've always been able to run Linux under VPC and VS, as the virtualized hardware is pretty much lowest-common-denominator stuff. The recent announcement was around both support and the fact that additions were created and released for a list of about a dozen popuplar distributions.
A little known fact is that the development and support of the additions was outsourced. This was mainly done to avoid "polluting" the VS/VPC products with GPL and other Open Source licenses that require re-released of derived code. The same company which created the additions is also the one doing the support - when a customer calls with a Linux issue, Microsoft supoprt just passes the call on to the support company, with the charges being under the Microsoft support model. This sort of thing isn't unusual. What *is* unusual is internal Microsoft employees can't even use the additions, as installing them requires kernal code in the virtual machine, which is against their anti-pollution policy.
As far as the support level, it's essentially the same as for Microsoft's own OS, with the "commercially reasonable" caveat, which basically measn they reserve the right to stop if the time/resources required to run down the fix is unreasonable. What "unreasonable" means is of course subject to interpretation...