Microsoft's licensing of its Hyper-V hypervisor technology could double the licence fees in smaller businesses that do not run Microsoft's Enterprise or Datacenter site licence agreements.
Hyper-V allows users to run multiple virtual machines on the same physical server. Each node can run Windows Server as long as the business has bought a Windows Server licence. With the Standard Edition, businesses have the right to run one instance in a virtual machine with Enterprise Edition they have the right to run up to four instances in virtual machines, and with Datacenter Edition they have unlimited virtual instances.
Drue Reeves, research director at Burton Group, said, "Microsoft's licensing limits the ability for users to maintain their physical servers."
According to Reeves, when a user buys Windows Server standard edition (which includes Hyper-V), they are allowed to run only one virtual machine, and the ability to move the operating system (or another Microsoft server software) is limited by a 90-day "moratorium" when the virtual machine is moved to another physical server.
This could cause problems in IT departments when servers need maintenance. "The administrator cannot move the operating system back for 90 days. If he does, he will no longer comply with Microsoft licensing," Reeves warned.
Burton Group has evaluated the impact of the Microsoft licensing and found that users need to licence for any server the operating system could run on in a virtual machine environment. For instance, if a user runs an eight-node cluster where four nodes are configured to run Windows Server 2008 standard edition servers, the administrator would need to ensure the business has another Windows Server licence for each physical server where that OS might move to if a cluster node fails.
The licensing affects users buying Standard Edition licensing. Mike Schutz, director of product management for the Windows Server group at Microsoft, said, "Businesses can use the Datacenter edition or Enterprise Edition licence if they want to move the operating system freely between virtual machines."
How the licensing works
An office that consolidates two SQL Server 2005 systems onto one physical machine using a two-node server with Hyper-V would have to double its SQL Server 2005 licence investment. Since it is possible that the SQL Server 2005 VMs could both be on one server at a given time, you would need two SQL Server 2005 licences for each physical server.
So to run two instances of SQL 2005, you would need four licences. If you wanted to run them on a three-node physical host cluster, you would need six licences. At that point, you would qualify for a volume licensing discount. Volume licensing pricing is available for Microsoft server applications sold in quantities of five or higher.
Source: Burton Group