Working out how much virtualization is going to cost you has always been tricky, and it's certainly not getting any easier.
For example, VMware made a major change to the way it licenses vSphere -- part of its hybrid cloud infrastructure suite -- when it launched vSphere 5 recently, and it hasn't exactly made it straightforward to work out what the implications of that will be.
How does it work? Here goes: There's a per-CPU socket pricing element, as there was before, but there's also a vRAM entitlement that goes with that, and the amount of entitlement depends on the vSphere edition for which you buy a license. You can pool vRAM entitlements from licenses for any given edition of vSphere, and you dip into this pool to cover the configured memory of every powered-on virtual machine. Got that?
What happens if your pool runs out? In vSphere Essentials and Essentials plus you will not be able to power on a virtual machine if doing so would take you over your pooled vRAM entitlement, but in vSphere Standard, Enterprise and Enterprise Plus you will be able to, although you'll get a warning.
But will it cost more than before? In a VMware faq, the company explains that "Although it is impossible to predict the effects of the new model in every type of environment, the licensing model has been designed to minimize the risk of potential impacts in existing environments while also providing room for growth."
There's a problem here. Actually there are a few problems. One is that it's not clear what on earth VMware's answer means, but as far as one can tell, the company is saying it doesn't really know, and hopefully any cost increases will be small. Not very helpful, is it?
But the bigger problem is that every time VMware (NYSE: VMW) changes its licensing structure it becomes more obvious that future virtualization costs are essentially unpredictable. "It's based on RAM allocated, not RAM used," said Rohit Rahi, a Microsoft product marketing manager. "That's a huge, huge, huge difference. And [VMware's] licensing model has changed three times in the last three years, so what's the reliability that it won't change again in six months?"
This uncertainty presents a big opportunity to Microsoft (NASDAQ: MSFT). Its Hyper-V virtualization technology ecosystem is beginning to grow up now. Gartner ranked the company a virtualization leader in its recent Magic Quadrant, alongside VMware and Citrix. More to the point, one of the benefits of Microsoft's virtualization technology is that it is cheap -- at least compared to VMware's.
Earlier this month, Jeff Woolsey, Microsoft's virtualization group program manager, gave a sneak peak of the next version of the Hyper-V hypervisor in Windows Server 8, at its Worldwide Partner Conference. The hypervisor now supports more than 16 virtual processors per virtual machine. It also includes a feature called Hyper-V Replica, an asynchronous application consistent virtual machine replication system built into Windows Server 8. It works with any server network and storage vendor, and it provides unlimited replication out of the box. That's right -- unlimited replication for an unlimited number of virtual machines.
That's important because vSphere 5's replication, in the Site Recovery Manager module due out in Q3 2011 will cost customers extra. And not just that, customers will also have to fork out $195 to $495 for every protected virtual machine. That could quickly total up to quite a hefty replication tax.
Hyper-V replication may cost nothing, but prices can be deceptive, and you don't always pay what you think in the virtualization world. At WPC the company also told its partners that the money lies in the management. "Every $1 in Microsoft server virtualization software sold generates $34 in sales of complementary products and services for partners," said Sally Kim, the company's competitive strategy director.
That doesn't mean Hyper-V isn't cheap -- it's just that it may well cost you more than you think.
Paul Rubens is a journalist based in Marlow on Thames, England. He has been programming, tinkering and generally sitting in front of computer screens since his first encounter with a DEC PDP-11 in 1979.