Recently Microsoft made several licensing changes in regards to running its products in virtualized environments:
...Microsoft is updating its software licensing terms for 41 server applications, including Microsoft SQL Server 2008 Enterprise edition, Microsoft Exchange Server 2007 Service Pack 1 Standard and Enterprise editions, Microsoft Dynamics CRM 4.0 Enterprise and Professional editions, Microsoft Office SharePoint Server 2007, and Microsoft System Center products. With the new terms, the company is waiving its previous 90-day reassignment rule, allowing customers to reassign licenses from one server to another within a server farm as frequently as needed. For many customers, the change will reduce the number of licenses they need to support their IT systems, increase agility, and simplify the tracking of application instances or processors because customers now can count licenses by server farm instead of by server....
The Technet blog provides an example of this in practice:
A customer has a server farm with 8 4-processor servers, running a total of 4 copies of Exchange.A customer has a server farm with 8 4-processor servers, running a total of 4 instances of SQL Server Enterprise Edition under the per-processor model.
- Under the old rules, they would need to either manually move the Exchange instances to another server that is already licensed for Exchange, OR they would need to license all 8 possible servers for Exchange.
- Starting Sept. 1, they will need to have a license for each running instance (4) and those licenses can be moved from one physical server to another as needed.
- Under the old rules, the customer would need to manually move an instance from one licensed processor to another, or they would need as many as 32 licenses (8x4)
- Starting Sept 1, the customer will need a maximum of 4 licenses. Because Microsoft allows unlimited instances on a processor licensed for SQL Server Enterprise Edition, the customer could have as few as one license if all 4 instances are always moved together.
In addition support has been added for 31 server applications on WS08 Hyper-V, Microsoft Hyper-V Server or any other validated hypervisor. At present VMWare has not been validated. The Burton group points out a couple significant limitations however. The 90 day transfer restriction is only lifted for volume licensing. The licensing changes also do not apply to server operating systems.