Apple allows virtualization of Mac OS X Leopard Server

“In a notable about-face, Apple has changed its stance with regard to allowing Mac OS X Server to be run inside a virtual machine (VM), much as Parallels Desktop and VMware Fusion make it possible to run Windows and other PC-based operating systems on a Mac. Until the release of Mac OS X 10.5 Leopard Server, Apple’s software license agreement explicitly forbade running multiple copies of Mac OS X Server on a single Mac, preventing Parallels and VMware from including Mac OS X Server among the operating systems that could be virtualized legally,” Adam C. Engst reports for TidBITS.

Engst reports that Apple’s Tiger Server software license agreement reads:

This License allows you to install and use one copy of the Mac OS X Server software (the “Mac OS X Server Software”) on a single Apple-labeled computer at a time.

Engst reports, “However, a sharp-eyed systems engineer noticed that Leopard Server’s software license agreement is significantly different. Dave Schroeder, Senior Systems Engineer at the University of Wisconsin-Madison, posted to the mailing list about his finding, calling out this change:”

This License allows you to install and use one copy of the Mac OS X Server software (the “Mac OS X Server Software”) on a single Apple-labeled computer. You may also install and use other copies of Mac OS X Server Software on the same Apple-labeled computer, provided that you acquire an individual and valid license from Apple for each of these other copies of Mac OS X Server Software.

Engst reports, “This change applies only to Leopard Server, not to the desktop version of Leopard. Apple has not changed the software license agreements for either version of Tiger.”

Much more in the full article here.

[Thanks to MacDailyNews Readers “macdaddy4nr” and “Too Hot!” for the heads up.]


  1. This is a big deal. A number of articles in the computer trade press over the years have given one reason why enterprise customers are not interested in OS X Server as the lack of virtualization.

    Of course, Apple doesn’t have a heavy duty sever to go with change. Virtualization usually takes place on 16, 32 and bigger chip systems.

    But, maybe this also presages a change there as well. With 4 core chips, just maybe Apple will finally come out with a 2U server with 16 cores. That could use this new license.

    2U 16 core servers are cheaper to buy, and run, than two 1U 8 core servers. But, they can’t always be utilized fully. That’s where virtualization comes in.

    Hopefully, Apple will come out with those larger models soon.

  2. “Is this something people who use *current* (as of October 31 2007) Apple server hardware would care about?”

    While current machines could use it, it wouldn’t make that much of a difference, as current machines, used for the tasks they are normally bought for, are heavily utilized already.

    I can’t help but think this will lead to the much requested 2U model.

  3. This is an incredible turn of events!

    Although this is a really limited window of opportunity for virtualization, I think this is Apple’s “measured and controlled” way of experimenting with virtualization. Getting more experience and knowledge on virtualization may allow Apple in the future to license VM versions of Leopard server or future server OS X versions to non-Mac servers.

    If Apple eventually allows virtualization on non-Macs, Leopard will instantly be “played” with in server rooms around the world, giving sys. admins a taste of what it’s like. I believe this could easily be the corporate world equivalent to what the Intel transition and bootcamp have been for consumers.

    Is this a sign that Apple is really planning an all out assault on the server market?

  4. Virtualization is a fab, There is no performance improvements with virtualization, in fact just the opposite is true. With VMware you buy a $22,000 VX Server and the VM Server software is installed you can run at most 3 Windows 2003 Server virtualized at once before the system is noticeable slow. Which makes the cost per server about $7,333.00 plus the cost of Windows 2003 server licenses. Foe that much money I can buy a lot of Cheap Windows PC’s and get better performance out of them. But, If your company as more money then brains I guess virtualization is the right choice.

  5. You’re missing the point. With large, many core servers, all of the cores are often not being utilized. Going virtual, they will be. It’s all about load balancing.

    Servers that are fully utilized won’t be virtualized, that’s not it’s purpose.

  6. Good point, will the power of XServers step up to this? I don’t think Apple will cave any time soon in letting it be virtualized on non-Apple branded hardware, though I don’t think that would necessarily be a bad move for Apple…

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