Virtualization industry observers expect Microsoft (Nasdaq: MSFT)to eliminate a licensing restriction that has hampered the mobility of virtual servers, perhaps as soon as next week.
Under current Microsoft rules, software running on a virtual machine is licensed based on the physical server. This can be problematic because of technologies such as VMware’s (Nasdaq: VMW) VMotion, which can move virtual machines from one physical server to another without causing downtime.
Microsoft considers a VMotion move a license transfer, and prevents customers from making such a transfer more than once every 90 days.
“You may reassign a software license, but not on a short-term basis (i.e., not within 90 days of the last assignment),” Microsoft says in a licensing policy document for Windows Server 2003.
This 90-day restriction also applies to SQL Server 2005 and Exchange Server 2007.
“Technically, the virtual machine would have to remain on the same physical machine for three months,” says Burton Group analyst Chris Wolf, who has written extensively about licensing on virtual servers and urges vendors to lift such restrictions.
In an interview last month, Wolf predicted that Microsoft would respond to customer concerns and eliminate the 90-day restriction, and instead tie licenses to virtual machines rather than physical ones. “Within a few months we’re going to see those changes,” he said. “I believe the 90-day restriction will go away.”
Patrick O’Rourke, group product manager at Microsoft, discussed the 90-day restriction and said Microsoft is considering licensing changes that would give customers more flexibility in reassigning virtual machines, which could take place sometime next week.
A Microsoft spokesperson said the company will announce licensing changes as early as next Tuesday.
“As server virtualization becomes more mainstream, Microsoft will be announcing new licensing and support policies to help customers make their data centers and enterprise IT more dynamic on August 19,” Microsoft said.
The exact changes haven’t been revealed. Lifting the 90-day restriction would give Microsoft customers an ideal set of licensing policies for virtual environments, according to a January report written by Wolf titled “Virtualization Licensing and Support Lethargy: Curing the Disease that Stalls Virtualization Adoption.”
Microsoft already supports multiple virtualization platforms and gives customers several licensing options tailored both for small businesses and large enterprises.
“Allowing Standard Edition Windows Server OS licenses to be assigned directly to a VM and move with a VM without restriction is all that is needed for Microsoft to offer the most nearly ideal licensing terms,” Wolf wrote.
Most vendors are making a good-faith effort to offer fair licensing terms, says analyst Charles King of Pund-IT Research. “Vendors are working hard to come up with schemas that work well and are fair to them and the end customer,” he says.
But adapting licensing to data centers where virtual machines can be created in an instant and moved just as quickly is challenging.
Multi-core processors add to the complexity. Vendors are still grappling with the question of whether to charge license fees for each server, core or socket, or use some other calculation to determine the value of software.
Virtualization, meanwhile, lets IT managers operate multiple virtual servers on a single core.
In virtualized data centers designed for high availability, “you’ve got the ability to spin up additional virtual machines as your processing demands increase,” King says. “The difficulty with software licensing is how you keep track of how many virtual machines, how many applications, or how many iterations of the operating system you’re running at any time. … It’s an interesting can of worms.”
