Case Studies


Budget-Conscious College Achieves Balance with Virtual SAN

classroom macThe IT department at an Oregon-based college manages two open-use computer labs and one computer-equipped classroom. Because of financial restrictions, the college had originally purchased all of its servers with local storage, but that infrastructure could not handle the school’s growing workloads, and it required time-consuming upkeep. The college turned to the new VMware Virtual SAN™ product, which addresses these and other concerns while offering a simple and scalable solution that fits within its budget.

The Challenge

The college’s computer lab infrastructure was procured over time. With the increasing use of technology in the curriculum, the loads placed on the computer lab infrastructure were outpacing bandwidth.

“I had spec’d out for a continuous user cycle of 5 to 15 users at a time,” says the college’s system administrator. “But now we’re seeing a 50-user turnover in 10 minutes. The system couldn’t handle that load.”

The three-person department tried to manually balance the load over four servers and 12-plus network pools, but the system still experienced outages or “boot storms” (a loss in service during peak usage), requiring as many as 20 minutes for users to log in. Beyond that, system maintenance was extremely time-consuming, with a full recompose (a reset of the virtual desktop) taking as long as 10 hours.

“The memory load went way up; the turnover load went way up; we were running out of IOPS; and we couldn’t balance properly because it was all local storage, which clearly doesn’t work,” recalls the system administrator. “It was a perfect storm.”

The IT department knew they couldn’t add more desktop storage; the lab environment was far too dynamic for that. Yet the cost of a traditional storage area network (SAN) that could meet the college’s requirements of 130 to 170 concurrent users was simply not in the budget.

The Solution

The system administrator briefly considered a Nexsan SAN storage array, but it was a hardware-based solution that would require a significant up-front investment. He also considered other all-flash and hybrid solutions. “But I’m a huge fan of VMware’s software-defined storage vision,” he says. “It’s where the market is going.”

So when the VMware Virtual SAN product became available in March 2014, he jumped at the opportunity. “It was very similar to what we were looking at, but now [the capabilities are] baked into the hypervisor right at the kernel level, which is significantly more efficient than what we use today.” Plus, it’s designed for use with other VMware products, such as the VMware Horizon® View™ solution, already in use at the college.

The IT department didn’t have the time or resources to conduct a proof of concept—the system had to be online before the summer class session began so it could be tested and refined with lighter workloads. With help from VMware technical support and other early adopters of the product, the system admin installed the Virtual SAN solution for 190-plus desktops over just three network pools. The pools deployed in about 20 minutes. “Two clicks and you’re done,” the system administrator says. Integrating an additional server took just four hours.

“It was the perfect solution to allow us to take advantage of all the storage we already purchased as well as dramatically increase the performance of the current system without having to spend $100,000 on a new SAN.”

Virtual SAN

Business Benefits

The Virtual SAN solution went live on June 20 with great success. Once the Virtual SAN software correctly clustered the servers, the Horizon View solution was able to balance workloads for more consistent performance. Now, even with 60 users on a single network pool, there are no boot storms, and users can sign on in under a minute. The system administrator expects the same performance this fall when the system is at full capacity of 170 users. Students and faculty will enjoy uninterrupted service, even during peak load periods.

Managing storage is also far easier, giving the team time to work on other critical tasks, such as moving the labs to a brand-new facility this fall. “It’s night and day,” the system administrator explains, noting that the labs can now be recomposed in less than two hours. “And instead of having to do it 12 times, we can do it just three times, which means the number of human errors decreased by an order of magnitude. Our ability to reimage midstream also went way up.”

In the future, firmware upgrades will be less risky because there is no single point of failure, unlike with a traditional SAN. Similarly, expanding the system is as easy as adding an additional server. “Before Virtual SAN, we had no ability to scale. Now there is a much better and more controllable cost per desktop. And it’s a piece of cake; if I want to add additional capacity, I just add an additional server. I don’t have to worry about whether my SAN can grow or not.”

That’s good for the budget, especially for a public institution with limited funds. “I can scale one small chunk at a time without having to worry about this huge monolithic SAN that I have to replace in five years,” the system administrator says. “I can justify $25,000 to $30,000 every year for a new server.”

Looking Ahead

The IT department is already planning for the day when the college can offer ubiquitous, 24/7 student access to the network, so users won’t have to be tied to the labs. “That’s the holy grail we’ve been after the whole time, but we didn’t have the capacity to do it. We were barely hanging on to our own endpoints,” he says. “But now I can generate capacity easily. That’s really the next big piece for us.”