We’ve covered  Server and CAL and Processor based licensing, so I thought it might be useful to cover off some guidelines scenarios to help think through how this pans out in a day to day basis.

If you haven’t already done so, I also recommend that you read my post on licensing SQL Server in a virtual environment and the other one on SQL Server Licensing and redundancy.

Virtualization, logical CPU’s and cores

With this in mind, here is a scenario that floated into my inbox over the last week or so.

“A hyper-v server with 2 quad core procs, SQL Server on one virtual machine with 4 virtual procs assigned to it, BizTalk Server on another virtual machine with 4 virtual procs assigned to it. That's 1 SQL licence, 1 biztalk licence, and 2 window server licenses right? (other than the host)”

The licensing suggested in this scenario is unclear and depends on options used.  For example you could license this environment as follows (putting BizTalk aside):

Component	License Entitlements
Windows Server Enterprise	1 physical host + 4 virtual hosts (CPU count doesn’t matter)
SQL Server Server Standard & CAL	License for virtual machine – CPU count doesn’t matter

If you wanted to license SQL Server by processor for SQL Server standard, you would need only need one processor license because SQL Server Standard is licensed per logical processor (so four processors in this example) – however there is a conversion for the number of physical cores in this scenario (eight cores in this example).  The calculation is logical CPUs divided by physical cores – so four divided by eight (rounded up) equates to one license.

But what if you wanted to take advantage of transparent encryption, compression and some of the other SQL Server Enterprise features?  Here there is a difference between SQL Standard and Enterprise when it comes to virtualization – the SQL Server Enterprise license actually caters for virtualization. 

So to license this scenario for SQL Server Enterprise per processor, you would need a two processor SQL Enterprise license – as SQL Enterprise is licensed at the Physical CPU level – regardless of the number of virtual hosts or CPU’s.  SQL Server Enterprise then allows you to have as many virtual machines on the server as you want to, all running SQL Server Enterprise Edition.

If you wanted to license this by Server and CAL – you would buy a single SQL Server Enterprise license – for the physical machine – and you automatically get unlimited virtual instances on that one machine. Because the clients are licensed by CAL, you don’t need to worry about licenses for the number of servers.

What about if you wanted to do this on Xen (as another customer asked me the other day)?  SQL Server itself doesn’t care what virtualization platform you use, and the license doesn’t change.  In fact we support SQL Server on a range of Virtualization platforms.

If you are unsure about some licensing scenario, please send me an email and I can write it up in a future blog post.