April 30, 2007
A. Running Microsoft Virtual Machines on Third-Party Virtualization Software
Update: Microsoft’s usage policy as described on Microsoft.com has been revised. Microsoft’s clarification is a significant positive step for end users.
Feb 24, 2007
March 28, 2007
B. Activation of Microsoft Virtual Machines on Third-Party Virtualization Software
Addendum: Under Microsoft’s VHD Test Drive program, ISVs are required to distribute Windows-based virtual machines only in Microsoft’s VHD format, as well as activate these demo virtual machines with Microsoft qualified tools, which are currently limited to Microsoft Virtual PC or Virtual Server. Third-party virtualization products that use virtual machine disk format technology other than Microsoft’s are thus excluded from Microsoft’s virtual machine software distribution program, even though these products are fully capable of running Windows virtual machines robustly. Moreover, once these virtual machines are activated in a Microsoft virtualization product, Microsoft’s existing anti-piracy and activation mechanisms will cause these pre-activated virtual machines to de-activate when they are run on other virtualization products, such as VMware. An example of this effect is this Internet Explorer / Windows XP trial VM. Microsoft should allow ISVs to create Windows virtual machines in whatever product and virtual machine format they prefer.
C. Server Virtual Machine Mobility
Addendum: Microsoft’s licensing policies for virtualization allow for instances of Windows OS and server applications running in VMs to be moved from one physical server to another as long as the source and target server are both properly licensed for the OS and server application.
This is what Microsoft calls “moving an instance of software” and is what VMotion does. For example, if two servers are attached to a SAN where multiple virtual hard disks contain both Windows Server 2003 and Exchange, these instances can be moved from one physical server to another as long as both physical servers are each assigned Windows Server 2003 and Exchange licenses.
Customers want to be able transfer their actual software licenses from one server to another without burdensome restrictions in the same way as they can move instances of software in virtual machines freely from machine to machine. Most application vendors enable this by allowing licenses to be tied to virtual machine environments as opposed to physical hosts, letting customers move software instances in virtual machines among physical host machines as necessary. This policy confers significant benefits in terms of uptime and operational flexibility, and should be adopted broadly by software vendors.
In contrast, Microsoft’s licensing policy has some restrictions on transferring licenses from one server to another. Under Microsoft licensing, Windows Server licenses are tied to physical hosts and do not move with virtual machine environments. Reassignment of a license to another server is only allowed once per 90 days except in case of hardware failure, and for more frequent license reassignments, customers are required to separately license each machine to run the server software. This means that the customer will have to either purchase additional Windows Server Standard or Enterprise Edition licenses to cover the potential number of virtual machines that may run on each host machine, or upgrade their Windows Server licenses to Datacenter Edition.
October 2006
For customers who choose to use Windows Server Datacenter Edition, which allows an unlimited number of Windows instances in virtual machines on a single host, there is no problem. On the other hand, for customers who have pre-existing license agreements based on Windows Server Standard or Enterprise Edition, this can be an unnecessary and illogical inconvenience.
Customers need a pragmatic, unencumbered model where users are not forced to either buy incremental licenses or shift to an “all-you-can-eat” model in order to leverage virtual machine mobility.
D. Virtualization for Hosted Desktops
On Monday April 2, 2007, Microsoft announced a new licensing model supporting server-based hosting of virtualized Windows desktops, called Windows Vista Enterprise Centralized Desktops (VECD). VECD enables customers to deploy and run Windows Vista Enterprise in virtual machines on server hardware, and access them using remote PCs and thin clients, and is available to Microsoft Software Assurance customers for an annual, per-device subscription fee. The fee varies based on whether your business is licensing PCs or thin clients to access the virtual desktop, and Microsoft has not released the subscription fee schedule. This mode of licensing applies to Windows Vista Enterprise with Software Assurance, and customers can use “downgrade rights” under their Software Assurance agreement to deploy any version of Windows Professional editions (Windows 2000 Professional, XP Professional, and Vista Enterprise) in a virtual machine.
E. Mobility for Virtualized Desktops
Microsoft has stated that customers with a retail version of Windows XP or Windows Vista have similar assignment rights that permit the license for the software to be assigned from one device to another without any restriction on the number of time the license may be assigned. The software must however be uninstalled from the first device before assignment.
F. Availability of Virtualized Windows for Desktops from OEMs
Microsoft has stated that with the introduction of Vista, PC OEMs do now have some capability to ship Windows clients in virtual machines. It is not clear what scope or restrictions apply to this.