So back in July 2011, when VMware announced vSphere 5 to the world along with its controversial new licensing model, VMware's competition was quick to join the hue and cry from customers that felt VMware was taking away something that, until then, was free.
You can Google it yourself; just put "vTax" in your search bar and you can get lost in all the write-ups, venom and FUD.
One of my favorites is a TechNet article from the Microsoft virtualization team that attempts a side-by-side cost analysis between vSphere 5 and Hyper-V, showing how the increasing RAM and core density of a single server causes rapidly-escalating prices for licensing. While the author presents reasonable math on the cost to migrate from low(er) density hosts to high(er) density hosts, I have yet to see real-world Hyper-V support the consolidation ratio of VMware. In my personal experience, I've been unable to start up three 2GB VMs on an 8GB Hyper-V system for a classroom environment, while I've run five 2GB VMs on an 8GB ESXi server. In both cases, the host was strained to the point that the running VMs (2 vs 5) were sluggish and slow to respond, but I use the example to suggest that at scale it could take 50% less VMware infrastructure compared to Hyper-V, making a 10-to-10 cluster comparison no more appropriate than comparing apples to oranges for Vitamin C nutrition. And while both products have a limited set of approved/supported platforms for hardware compatibility, the VMware set is much broader than Hyper-V, giving the purchaser more options for savings that can offset the raw costs of licensing.
And on top of all that, Microsoft marketing money also paid for a spoof of VMware with the "VMlimited" microsite.
But today, Microsoft exposed its hypocrisy by unveiling a new licensing model when they announced the next version of SQL Server, SQL Server 2012.
In the same way that VMware is accused of "taking back" free features and benefits, Microsoft has done the same by eliminating the per-processor (socket) licensing option in favor of a per-core (physical thread of execution) model.
Like with VMware's old model, the old model for SQL Server allowed organizations to provision high(er)-density servers (in terms of both RAM and cores-per-socket) in place of low(er)-density servers without running into the need to acquire new licenses. The new model takes that away, and also puts the burden of reoccurring subscription expenses (Software Assurance, or "SA") into the mix in order to best-leverage the combination of SQL Server and virtualization.
Under the old model, an organization could pay $164,970 (USD, list) for six sockets of SQL Server Enterprise Edition; in a 6-socket VMware cluster, a DBA could then implement an unlimited number of SQL instances on up to 8 VMs per host. If the organization paid an additional $41,244/year for SA, the VMware cluster would be able to run unlimited instances on an unlimited number of VMs (subject to OS licensing limits—if any—and resource constraints of the virtual environment). Further, the old model had no limitations for the migration of SQL-hosting VMs from one server to another (i.e., vMotion). With modern, high-density servers that provide 512GB RAM and 24 cores of execution per 2-socket box, it's conceivable that dozens of multi-vCPU VMs could be hosted for costs in the neighborhood of $365,000 over a 5-year period.
Now compare that to the new model. At a (list) price of $6874 per core, that same six-socket, 12-core-per-socket cluster would cost $494,928 plus an additional 25% annually for SA, making the 5-year cost for the same hardware environment in excess of $1.1 million.
That's a 300% increase in costs for the new licensing model.
Hmmm.... Shall we now call per-core licensing the SQL Tax?