Server-hosted VDI is only one of many desktop virtualization technologies IT pros combine to deliver Windows desktops today.
A lot of people have been fooled by VMware's one-size-fits-all model of VDI. But you can't do VDI everywhere.
systems architect, Kingston University
Companies that virtualize desktops use a mix of VDI, application virtualization, Terminal Services, workstation virtualization and other remote desktop delivery technologies, according to the recently released 2011 Virtualization Decisions Survey of over 500 IT pros conducted by SearchServerVirtualization.com.
Of the respondents who virtualize desktops, 57% said they use VDI for virtual desktops, 54% said they use workstation virtualization, 53% use application virtualization and 50% of respondents said they use Terminal Services.
Mixed virtual desktop environments seem to be particularly common at colleges and universities, where IT needs to deliver desktops and applications to a diverse population of end users that need to access desktops from various locations.
Kingston University in the U.K., for instance, moved from traditional PCs to a mixed virtual desktop/Terminal Services/PC infrastructure when it upgraded to Windows 7. The school shifted its desktop model to simplify desktop management -- a common reason IT pros adopt desktop virtualization technologies.
In the heyday of Windows XP, the IT department supported about 7,000 PCs and about 200 applications using Active Directory and other management tools. But when Windows7 began to dominate, IT had thousands of applications to install on client devices used by some 25,000 end users, including Macs, Linux boxes and PCs, said Dan Bolton, a systems architect for Kingston University.
"We pushed our Windows deployment model to the limit with XP, so Windows 7 was our catalyst for change," Bolton said. "Students and faculty simply use more applications, and there are more applications out there. So, we had to adapt and expand our infrastructure to support that growth."
Bolton performed trials of a huge variety of desktop virtualization products in the market before settling on Quest Software's vWorkspace and Microsoft virtualization technologies.
"One thing we have learned is that you have to do your own homework and a lot of your own assessments," Bolton said. "A lot of people have been fooled by VMware's one-size-fits-all model of VDI. But you can't do VDI everywhere -- the technologies aren't there yet."
He chose Quest and Microsoft because the software is less expensive and Quest's software runs on more than one type of server hypervisor.
"We were headed down the VDI road with VMware, because we used them for servers, but they see education as a revenue stream, which doesn't work here in the U.K.," Bolton said. "Now, we use Hyper-V on servers and Quest desktops and save [349,000 U.S. dollars] per year."
The desktop environment at Kingston University now consists of about 4,000 Terminal Services seats and about 1,500 VDI seats -- both based on Quest vWorkspace and Hyper-V/RemoteFX. There are also many physical PCs running virtualized applications delivered with App-V and some faculty members use applications virtualized with Application Jukebox software from Endeavors Technologies. Additionally, RES Software's orchestration suite is used for profile management and system automation.
"It sounds complicated, and nobody would believe me if I told them, but I am able to manage this mixed environment myself," Bolton said.
He manages everything with Quest Foglight for Virtual Desktops 5.6, which automates infrastructure monitoring and capacity management. It replaces the open source monitoring system he used to use from Nagios.
"It served us well in the past but isn't right for virtual desktop infrastructure and Hyper-V," Bolton said. "We needed an easy access point to see where the problems actually lie so we can fix problems before they happen."
The Foglight for Virtual Desktops tool also helps IT determine resource allocation and provides insight into networking to monitor RemoteFX, network throughput and monitor IOPs for VDI machines.
"It gives us a way to tell if we have enough resources, or if we need to give our storage guys a box of chocolates for additional capacity," Bolton said.
UConn's virtual desktop mix
The University of Connecticut (UConn) is another example of higher education delivering desktops with various types of software. UConn began testing VMware View 4.6 last fall and now has a mix of PCs and hundreds of virtual desktops deployed on VMware vSphere-based Dell PowerEdge servers.
"Desktop virtualization covers a spectrum -- there isn't one way to use it," said Jeremy Pollack, director of IT at the UConn School of Business. "We learned that very quickly."
Pollack uses Unidesk software for personalization layers to give end users an experience similar to what they'd get with a PC, which includes the ability to install their own applications and maintain their settings.
The move to virtual desktops means simpler management, and it should lower hardware costs for UConn, which plans to replace its end-of-life Dell PCs with thin clients. It might also extend the life of old PCs with Windows ThinPC before moving to thin clients, Pollack said.
Similarly, more than 45% of companies that use desktop virtualization say lower hardware costs are the reason they moved to virtual desktops.