One of the topics that gets raised regularly with the OEM Server team is around when you should discuss selling the Datacenter vs. Standard editions of Windows Server 2012 R2 to customers, and usually it's easy to extract a few details about the customer scenario that will help shape those conversations. The main thing that needs to be taken into account is the number of virtualised Windows Server instances the customer needs to run on each server, but you also need to take into the account the potential number of Windows Server virtual machines you may need to run when you hit particular types scenarios. This is a high level overview, it's not going to present
Even though this initial piece is mostly focused on licensing, when in doubt with licensing issues make sure you contact your distributor or Microsoft licensing specialist to verify that what you want to supply to your customers will cover them from a licensing perspective. The different Microsoft licensing agreements are the source of truth for these things, and nothing in this post overrides or hopefully contradicts those.
Let's move on now and discuss those particular types of scenarios where the basic recommendation about the number of Windows Server VMs per server may not be as simple as you think. For the purpose of this post, let's focus on server recovery or even host server patching scenarios which have a great deal in common, with the major exception being the planned versus unplanned. Let's start with a simple scenario - a customer needs two servers to support Hyper-V's shared nothing Live Migration capability or Hyper-V Replica.
With a license for Windows Server 2012 R2 Standard per server, Server1 and Server2 would each be licensed to run two Windows Server virtual machines. If only two VMs are running per server, the customer is in compliance with their licensing. A critical update becomes available that needs to be installed on the Hyper-V host, and this update requires a hardware reboot. If the customer doesn't need the two virtual machines running on that server to be available during the server hardware restart, then the conversation is effectively done.
However, if the customer decides that they would like to perform Live Migrations and have all four virtual machines running at once on the second server, this means that server needs to be licensed for four concurrent virtual machines. The VM rights for one server aren't temporarily transferable to the other server, instead you need to think about two different licensing alternatives. The first of these is stacking two Windows Server 2012 R2 Standard licenses on each server, which would give you four virtual machine usage rights.
You can see from this scenario that it doesn't take too many VMs to get to the point where Datacenter becomes more cost efficient than stacking additional copies of Windows Server 2012 R2 Standard, which you would need to be doing on a per server basis to cover your customer. While your customers may be shifting some workloads to the cloud, there are some customers you still need to support their current on-premises software, and looking at deploying more on-premises solutions in the future, some of these in order to integrate with or accelerate certain cloud workloads.
As we go through more posts in this series, you will see some of benefits that Windows Server 2012 R2 Datacenter brings to customers who may be teetering on the edge of going down the multiple copies of Standard per server versus a single copy of Datacenter per server, but the big one is licensing simplicity and helping your customers remain compliant.