Stretching IT Budgets with Open Source and Virtualization

• By Dian Schaffhauser
• 04/07/11

Jeremy Fluhmann knows how to stretch a dollar. The technology director for Winters Independent School District in Winters, TX had a budget that would allow him to refresh about 50 computers a year. That's just a fraction of the 650 to 670 end user devices he estimated his two-person IT team supports in the district. At that rate, it would take about 13 years to replace the entire population of PCs. And long before then, he pointed out, "We'd have old machines we still have to maintain."

Rather than bemoaning the slow speed of the refresh treadmill, Fluhmann has decided to step off and has begun implementing a mix of open source software and virtual desktops to extend the life of district equipment.

Fluhmann, a bit of a Linux and open source junkie, was trying out openNebula, an open source cloud toolkit that, when paired with Haizea, an open source resource manager, would allow him to schedule startup and shutdown of virtual machines. He said he remembers thinking that he could use some of the district's older computers to run the virtual machines in computer labs. This would allow a student to access applications from centralized servers instead of from the local, pokey drive.

To make that work, however, he needed to find a connection broker that would connect a specific machine to a specific image. He began doing various Internet searches using phrases such as "desktop virtualization open source," "open source connection broker," and "Linux desktop virtualization." That's when in September 2009 he stumbled across a Web site for Virtual Bridges and its product Verde, which is currently in version 5.

As he noted in a blog post, "I started reading through the documentation and getting a feel for how the product worked. As I learned that it used [a kernel-based virtual machine] and would run on a base install of Ubuntu, I started to see where this was going. Not only will it easily fit into my current infrastructure, but it runs on my favorite operating system, as well!"

Verde allows a user to work through a Web console on applications that are delivered from a server. On the backside, the application provides an integrated management console for provisioning, monitoring, and reporting computer usage.

Virtual Desktop Test Site
Fluhmann ran a demo edition of the Virtual Bridges virtual desktop infrastructure and eventually contacted the company, which came to the district to set up a proof of concept project. He had persuaded a high school technology application teacher to run the proof in her lab of 25 computers. Students would log in as normal and do their regularly scheduled work.

Aside from discovering that many of the students didn't know their domain login (but instead had been using a generic login instead), recalled Fluhmann, "For them, it was no different than their usual user experience."

A couple of other hiccups surfaced during the test. One was the existence of Windows roaming profiles, which conflicted with Verde. Once roaming profiles were eliminated, the conflicts disappeared.

Also, the proof of concept involved the use of Plato online courses, which tend to be multi-media heavy, Fluhmann said. "Out of 25 sessions, we were getting about 18 of them that could fully run the multi-media; for the rest of them the Flash media wouldn't show up." He said an underpowered server posed a limitation there.

In spite of those problems, Fluhmann said, he and the teacher were excited. First, they recognized how the use of virtual desktops could simplify management of those computers; they also saw how the use of Verde could give students access to computer lab images from their own machines at home for doing assignments without having to buy pricey software just for the class.

Also, some students had begun bringing in their own devices as teachers allow. The use of Verde gave those students a way to use their own devices to run specialized software in class they may not have installed. "From their laptop, they connect and run their session," Fluhmann said.

He made a business case for the long-term value of implementing virtual desktops to his district's superintendent, David Hutton, who negotiated a purchase of 550 licenses from Virtual Bridges. Part of that business case required a revised infrastructure to support a district-wide deployment.

Upgrade on the Infrastructure
"We knew we'd have to bump up the memory and processor on that server [from the proof of concept] or add another server," Fluhmann noted. Now the district has a cluster of four servers, HP ProLiant DL 385 G7s, each with 12 dual core AMD processors and 128 GB of memory. Using calculations from Virtual Bridges, he estimated that each server can handle about 200 simultaneous sessions of a light processing load, such as Web browsing, or about 120 sessions on a heavy load, such as video delivery.

Using an open source utility called GlusterFS, all of the servers point to network attached storage where the user files are maintained. "So no matter which server a user is working from, it's hitting the same storage," he explained. As he adds an additional server to the cluster, he'll be able to point it to the same storage "and it's good to go." Each user is granted 2 GB of memory space, but rather than preallocating the storage space before it's actually used, through the use of GlusterFS, Fluhmann expands capacity for each user as it's needed.

The overall price tag, he estimated, is about $100,000 for the hardware and the Virtual Bridges software licenses.

So far, Fluhmann has implemented Verde in two junior high computer labs, for a total of 45 PCs, as well as some administration offices. Next up will be the high school. The teacher he worked with on the proof of concept will be the first to get the new capability. He said he's hoping to build on that within the high school until it's fully deployed there. Then he'll also add it to the elementary schools.

At the junior high, the IT team was using FOG, a Linux-based open source computer imaging utility for Windows, to post patches and updates to district computers. "It worked OK, and it was a lot quicker than going to each computer to install software, make changes, and keep it up to date," Fluhmann said. "But when we wanted to install software to push out to those computers, I'd have to take one computer out and prep it with a new image, then push that out. It'd take a couple of hours to get all that done."

With Verde, he said, the process is to create a "gold image" on the server, install software that users need access to, then check it back in. "Everybody running a session based on that image will receive a notification that there has been an update to the image and that the computer needs to be restarted."

Once Verde is fully implemented in the district, he said, he expects to have to maintain four or five Windows images. Currently, the junior high has just one image containing all of the applications that are in use in the computer labs. At the high school, he'll need two images to start with--one for the technology applications teacher and another general image that will run in the computer labs, library, and other locations where student computers reside. He may also set up a Linux desktop image for use there too, "to offer that out to students so they can get in and experience it if they want to." The machines in use by administrative people contain specialized software for those users, such as the financial system.

Virtual Desktop Benefits
Although the district hasn't had any network outages yet, if it happens, the Verde sessions will break for the moment, said Fluhmann. But the students can pick up where they left off by moving to other machines that still have network connectivity. "Whatever they were doing before the network died," he explained, "all that stuff would still be up."

If the school has to close for some reason, such as a pandemic, Fluhmann noted, "we could still have classes as long as we could get computers to students. The student could connect from anywhere and run those lab images and do their work."

Fluhmann hasn't answered all of his own questions regarding the use of Verde in the district. For example, the district has a new laptop cart of Dell Inspiron Duos with convertible screens that allow the devices to be used as laptops or tablets. He said he doesn't know yet whether students will choose to use them natively or connect to their sessions "like they do in the labs."

Likewise, the junior high has a Mac lab with 25 iMacs and a cart with about 20 MacBooks. He said he doesn't know if those users are connecting to the Verde setup either. He said he hopes over the summer to hash that out with instructors "to make sure we're consistent with virtual desktop sessions." What he needs to sort out is whether those Macs are being used to teach Mac software or whether they're simply being used as computing devices. (On the subject of Apple devices, in 2010 the company released iVerde, a free app that allows iPad and iPhone users to access Verde-based Windows 7, Windows XP, and Linux desktops through their devices.)

In spite of these small bumps in the road, Fluhmann said, he anticipates multiple benefits with the desktop virtualization implementation, including fewer support calls, if the junior high experience is any indication. "We had weird issues," he said, "where on just one computer, the application would quit running. That went away since we manage a single image that all of the computers run. It reduces inconsistency on the hardware."

And he no longer has to keep up with a refresh cycle for computers that the district can't afford over the long haul. "Computers are getting more powerful, but for most of our stuff, we don't need that extra power," he said. "In a way it would feel like we were throwing away money to buy a general use computer and not really use it for even a fraction of its power. This way, we can likely go 10 years with these desktops."