IT professionals should not be lulled by the relative ease of implementing desktop virtualisation technology, according to a new report from Forrester Research Inc.
While licensing a desktop virtualisation product from your vendor of choice is straightforward -- count the number of users and pay a per-user fee -- making sure this new virtual environment remains in compliance with Microsoft licensing agreements is anything but easy.
"Licensing for desktop virtualization is different than with the traditional PC. There are new rules that you have to follow to remain in compliance," said Natalie Lambert, who covers virtualisation for the research firm.
Making matters riskier, Lambert said, is that operations folks have not had to think about Windows licensing before. That is the domain of their colleagues in sourcing.
Before moving forward with desktop virtualisation, operations people need to brush up on Windows licensing, she said, then be prepared to tell sourcing one of two things: "Either, one, 'We're playing around with this but don't worry, we're in compliance,' or two, 'We need to do the following in order to be compliant as we move forward with this strategy.'"
The CliffsNotes version: All roads lead to Microsoft Software Assurance (SA), the software giant's upgrade warranty when it comes to desktop virtualization. Without it, you are not entitled to run virtual desktops on your PCs as part of your Windows license, Lambert said.
Local desktop virtualisation with SA, and the Apple variation
Desktop virtualisation comes in two flavors: local and hosted. Local desktop virtualisation allows users to run multiple operating systems in a protected environment on their PCs.
"If you have that machine covered by SA, you can put up to four virtual machines on that laptop for no additional cost. Done," Lambert said. "If you don't have that SA for that base operating system, you have to buy a Windows license for it. So, if you have the base image and three virtual machines, you are paying Microsoft for four licenses."
The price of SA is calculated as a flat 29% of your current Microsoft licensing. Enterprises that decided SA was not worth the money might want to rethink that, given that SA will pay for itself after about two virtual machines (VMs).
A wrinkle or two: To run Windows on an Apple computer using software from vendors like VMWare or Parellels, you can buy a Windows license with SA for that Apple machine and run as many VMs as you want under your Microsoft volume licensing agreement.
"So you're basically buying an OS license you'll never use to enable you to run as many VMs as you want," Lambert said. "It's money for Microsoft. They're going to make money off all the Apples."
In addition, if you plan to use VMWare's Pocket ACE, the nifty device that allows you to put your desktop on a USB stick and run it on any computer in the world, no official Microsoft licensing exists for that.
"Brave customers are betting that Microsoft won't care as long as they license USB sticks as if they were physical machines," Lambert said, adding that Forrester expects Microsoft to come out with a licensing scheme for ACE shortly.
Hosted desktop virtualisation and VECD
Brace yourself: If you're going with hosted desktop virtualisation, staying in compliance with your Microsoft licensing agreement is a bit more complicated.
The first mandatory purchase is the Vista Enterprise Centralized Desktop (VECD) license. This is the subscription license required by Microsoft to run any Windows client operating system on a server in a data center. The license is needed independent of the hosted desktop virtualisation solution used, and its cost depends on the device connected to the hosted VM, Lambert explains.
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"If you are using thin clients, it is actually pretty easy. For $US110 [list price] per connecting thin client, you can access all the virtual environments," Lambert said.
If you are using a standard PC to access those virtual environments, however, Software Assurance (reminder: 29% of your current licensing cost) is back in the picture. For PCs with Software Assurance, access costs $US23 per device. And if you don't have SA? "You can't use them," Lambert said.
A wrinkle to consider: The benefit of using a standard PC covered by a VECD license, in addition to not having to buy all new thin clients, is that the named (not guest) users for those work PCs can access their work environments on their home PCs for no additional cost.
At the end of the day, licensing for this model comes down to the number of devices accessing the hosted desktop environment, Lambert said, not the number of users. So, the good news is that if you have 1,000 employees who share 500 computers, you have to buy only 500 VECD licenses. The flip side is that if you have 500 employees who roam 1,000 machines, you're buying 1,000 VECD licenses to stay in compliance.
Confused? You're not alone, Lambert says. "I can tell you this makes perfect sense to me, but that's because I spent two months with Microsoft to write this," she said.