In a recent SearchVMware.com tip, I outlined situations where it does not make sense to have SQL or Exchange virtualized. The bottom line is that licencing depends on many factors, and you need to consider licencing when virtualizing such applications or you could end up spending more money than necessary. One point worth noting that is not in the tip is if you opt to license Microsoft SQL Server per-processor, it may carry additional benefits.
The trick is to provide a VMware-based dedicated cluster, and license all processors in that cluster for SQL processor licensing. At that point, you can create an unlimited number of SQL instances on those processors. More information on SQL processor licensing and the unlimited features can be found on the Microsoft website. Couple that with Windows Datacenter licensing (which also allows unlimited virtualization rights), and you have a potential for a lot of SQL servers for a fixed price.
VMware’s recommendation for this scenario is to have a dedicated cluster for SQL servers with all processors licensed for SQL Server. My argument is that the initial cost of SQL licensing for all processors in a
dedicated cluster is an obstacle for most organizations. What is your take on virtualizing SQL Server in a dedicated cluster?