Windows Vista could spur corporate adoption of virtual desktop infrastructures (VDI) now that Microsoft has launched Vista Enterprise Centralized Desktops (VECD), a legal and relatively cost-effective way to license Vista in a virtual machine (VM). (See Microsoft intros virtualization-friendly Vista Enterprise license).
"Upgrading to Vista is one of the main drivers for VDI as a high percentage of corporate desktops (estimated around 60% to 70%) do not meet the minimum requirement for the new OS," emailed Paul Ghostine, co-founder and CEO of Provision Networks Inc., whose Virtual Access Suite connection broker software maps users to centralized desktops running in a virtual machine, on a PC blade, or terminal services.
Doug Strain, product marketing manager for virtualization at Hewlett-Packard Co., agrees that Vista upgrades are a potential opportunity for VDI. "I can imagine a scenario where people started saying, 'Gee, I really need to accelerate my transition to Vista.'" But in cases where an organization's existing desktop hardware can't support Vista, "you could redeploy it as a thin client and run Vista in VDI." Strain admitted he hadn't encountered any customers like these yet, but in light of VECD, he's "very enthusiastic."
Meanwhile, longtime participants in server-based computing are scrambling to adjust to the new VDI model. Tomorrow, PC blade maker ClearCube Technology will announce a version of its Sentral connection broker software that supports VMware ESX 3.x. Previous to version 5.5, Sentral only supported static connections between thin clients and blade PCs running in the data center.
Tom Josefy, ClearCube director of product management, said that customers with existing ClearCube blade PCs can reliably run up to 12 VMware virtual machines on one of its models, making it attractive to customers who want to extend ClearCube's thin clients out to less demanding users.
"Take healthcare, for example. Customers loved our solution for operating rooms and nurses' stations, but they wanted to deploy it across the board," Josefy said. "The one-to-one model solved a lot of environmental problems, but there were distance and cost limitations."
Atlanticare is an example of one those ClearCube customers. A healthcare system serving southern New Jersey, the firm has been started replacing its 3,000 desktops with ClearCube access devices and PC blades running VMware about a year ago. Most users share a blade with one or two other people, said Daniel Morreale, AtlantiCare CIO, and that a 2:1 ratio, the PC blades "come out even with desktop PCs" while delivering better security and easier management. At three users per blade, "I save a little bit of money."
New VDI licensing model
To further soften the cost blow, ClearCube plans to adopt special pricing developed by VMware for VDI environments. Instead of licensing ESX per box, ClearCube will offer customers the option to license ESX per virtual machine running on the blade. Pricing hasn't been finalized, but Josefy expects it will run about $200 per virtual machine when Sentral 5.5 ships next month.
HP also offers this model, said Strain, and it can be effective for shops that can't or don't want to run a lot of desktops on a single ESX host. For example, HP offers a 100-seat Enterprise ESX license for VDI for $33,275 including software and support (SNS). HP offers a comparable dual processor VMware Infrastructure 3 license for $6,957 list, putting the break-even point at about 21 VMs.
Strain said most of the VDI deployments HP has performed run on dual-processor systems with 8 GB to 16 GB of RAM. The servers are often blade-based and usually host between 15 and 20 virtual machines. In lab environments, he said, "we've been able to put considerably more users on there," but that in order to host more desktops, you typically need to add more memory in the form of 4 GB DIMMs. Prices for those memory modules are dramatically more expensive, Strain said, which "may be holding down densities on the server."
Brian Madden, an independent industry analyst specializing in server-based computing, thinks that licensing ESX per VM in VDI scenarios "is a cool idea." With VDI, he said, "the challenge is the perceived cost of building out your back-end infrastructure." A per-VM cost "would make it more like a traditional desktop computer," and shift the conversation away from back-end infrastructure costs to the pros and cons of virtual desktop infrastructures.
A per-VM licensing model will also work to prevent companies from building out needlessly dense ESX servers, Madden said. When ESX is licensed per box, "that encourages people to build the biggest server they can even if it doesn't make sense architecturally," Madden said.
AtlantiCare's Morreale, for one, doesn't plan to put more than three desktops per blade – not 12, like ClearCube's Josefy said was possible. "I don't know that I would do that; it would make me nervous. That's a lot of users if something goes down."
Let us know what you think about the story; email: Alex Barrett, News Director
Dig Deeper on Virtualization vendor comparisons