Do you mix production and non-production virtual machines in the same cluster? Then read this.

Recently, I have seen a few more “expert” recommendations claiming that Microsoft disallows use of MSDN in VMware clusters that also contain production virtual machines.

One of the authors referred to the following clauses from the Microsoft Product Terms:

1. One Licensed User may use any number of copies of the software and any prior version on any device dedicated to Customer's use for each User License it acquires.

2. Licensed Users may use the software for evaluation and to develop, test, and demonstrate Customer's programs. These rights include the use of the software to simulate an end user environment to diagnose issues related to its programs.

3. the software is not licensed for use in a Production Environment.

The author justified his position as follows:

1. MSDN is not licensed for use in a Production Environment.

2. Microsoft licenses are per device, not per virtual machine. The Production Environment is therefore determined by whether you have any production virtual machines on a host.

3. An MSDN license may not be assigned to a device, to which production licenses are already assigned.

The issue here isn't really that simple.

Somewhere around 2011-2013, I developed an eight-hour training session on MSDN licensing and auditing, commissioned by the Russian sub of Microsoft. At the time, there was no clear definition of Production Environment, and everyone interpreted it in their own way.

The position of the official "Licensing Group" within Microsoft kept changing, and by mid-2014 had become pretty negative: according to them, indeed, if there was at least one production machine on a host, no other virtual machine on the same host could use software licensed through MSDN.

However, Microsoft is a big company. And it has its own "islands” – product groups. The group responsible for development tools had a somewhat different viewpoint on how the software products created and managed by them should be licensed. After some internal bickering and constant nagging, a remarkable event occurred.

In October 2014, a clear and unambiguous definition of Production Environment was added to Product Use Rights (the precursor document to the Product Terms).?

From the Product Terms of September 2019:

Production Environment means any Physical or Virtual OSE running a production workload or accessing production data, or Physical OSE hosting one or more Virtual OSEs running production workloads or accessing production data.

So, what really happened here that is so remarkable? This: the scope of one independent Production Environment “cell" had finally been defined.?

It's not a server. it's not a blade. it's not a device. it's an Operating System Environment.

Thus, applicable licensing is determined by the specific purpose for which a particular virtual or physical operating environment (OSE) is used.

Of course, presence of a virtual production OSE on a host affects the licensing and restrictions on the use of MSDN on the physical OSE of the host. You must license the host with regular “production" licenses, and may not use MSDN licenses in the physical OSE.?

However, this does not apply in reverse to virtual OSEs on that host. And if any of those VMs do not perform production tasks and are not connected to production data, you may declare them "non-production" and install software under an MSDN license.

To remove any doubt, here's the definition of an OSE:

Operating System Environment (OSE) means all or part of an operating system Instance, or all or part of a virtual (or otherwise emulated) operating system Instance which enables separate machine identity (primary computer name or similar unique identifier) or separate administrative rights, and instances of applications, if any, configured to run on the operating system Instance or parts identified above. A physical hardware system can have one Physical OSE and/or one or more Virtual OSEs.

That is, each virtual machine is an OSE in its own right, within its own boundaries.

And here's an interesting thread in which you can, in a way, relive this wonderful story.

There is, unfortunately, another issue in the original article's author's logic. MSDN licences may certainly not be assigned to a device, but not in the sense that he has laid it out. The point is that MSDN is not, in principle, licensed per device. An MSDN license is assigned to a user.?

As usual, I hope this will help you save on Microsoft licensing costs.

And if you have any further doubts or questions, you know where to find me (hint: https://linkedin.com/in/golev)