Why SANs Make Sense

With 3,200 students, Aztec Municipal School District in Aztec, N.M., is much smaller than most big city districts, but it was nonetheless pushing up against the limits of its old storage systems when it implemented an HP LeftHand iSCSI SAN in August 2009.

“We were using direct-attached storage and internal server storage, which were effective on a small scale,” says Nathan Holmes, AMSD's technology director. “But once you outgrow the capacity or develop a mentality that starts focusing on uptime, fault tolerance and disaster recovery, you have to start considering a SAN.”

Protecting mission-critical servers and applications was an important reason for implementing the SAN at AMSD, says Holmes. Before installing the SAN, he and his staff had built redundancy into those systems by clustering servers connected to direct-attached storage, but they were still vulnerable if the storage device failed.

The district now links clustered blade servers to the LeftHand SAN, creating fault-tolerant arrays of storage across its networks to ensure continuity of operations and streamlined data retrieval, Holmes says. Ease of management and thin-provisioning capabilities, which allow the district to buy storage capacity only as needed, were other major factors in the decision to purchase LeftHand SAN technology, he says.

Aztec Municipal School District has plenty of company among K–12 districts that are now using SANs, says Andrew Reichman, senior analyst for Forrester Research. Burgeoning mounds of data, storage-intensive projects such as server virtualization and an increasing focus on green technologies that make more efficient use of data center resources are pushing school districts to consider SANs.

Large businesses have used SANs for nearly two decades – first Fibre Channel and more recently iSCSI products – to provide increased availability and redundancy for stored data, as well as centralized management of storage, says Reichman.

Part of the growth in SAN deployments in school districts can be attributed to the lower cost of iSCSI SANs compared with Fibre Channel products, which puts SAN technology within reach of more K–12 budgets, he says. Other considerations include the staff resources and skill sets available in school systems.

“Often K–12 districts are non-data-center environments, and they are managed by IT generalists,” Reichman says. “Fibre Channel SANs are wonderful, but they require a high level of expertise to manage them, and they're costly. iSCSI SANs are less expensive and easier to manage.”

Keep Pace with Changing Needs

When Memphis City Schools began to explore the benefits of server virtualization last year, it was clear that the district had outgrown its existing storage area networking technology.

With about 105,000 students in more than 200 schools, MCS used a Fibre Channel SAN for nearly a decade to help deal with its complex storage and retrieval needs, says Geneva Hawkins, MCS's director of information technology. But it was time to refresh the technology to keep pace with the district's evolving requirements.

“We were looking for a SAN solution that was easier to manage, a little more user friendly and would work for us long-term,” Hawkins says. “The solution we had in place was reaching end of life, and we wanted a technology that would fit with the other technologies we had in place, as well as our storage strategy going forward.”

After investigating every option, MCS purchased an HP LeftHand iSCSI SAN in October, Hawkins says. Lower purchase price and maintenance costs played a significant factor in the district's decision to go with an iSCSI SAN, but the IT staff also saw the technology as a better fit for MCS's environment, which does not rely heavily on high-bandwidth applications.

“Fibre is great, but for some environments it's a bit of overkill. We can do everything with iSCSI that we could do with Fibre,” Hawkins says.

Beyond the expected learning curve for any new technology, implementation of the LeftHand SAN proceeded without a hitch, says Dorren Ball, MCS's manager of enterprise support services. The benefits of the technology have been readily apparent to both end users and IT staff.

“Our customers are seeing faster performance, not only on the virtual servers but on access time to the databases,” Ball says. “Our backups are much improved over trying to do local backups on local servers. The SAN technology has cut our backup window by four hours a night.”

The large quantities of local storage that MCS had been using for its open systems were consuming substantial server resources, says Ball. Creating virtual servers on a VMware platform and shifting storage and backup to the SAN let the school system eliminate half of its physical servers.

By facilitating data center consolidation, the LeftHand SAN had essentially provided full return on the district's $220,000 investment in the technology in less than six months, she says.

“We have a practice that when we implement a new application, we buy five to 10 new servers,” Hawkins says. “We've implemented about 10 new applications since we installed the LeftHand SAN, and we haven't ordered even one new physical server.”

Easy Install

At Aztec Municipal School District, deployment of the SAN went smoothly and took less than a day, in part because the AMSD IT staff prepared by adding a VLAN and provisioning network ports for the SAN ahead of the actual installation, Holmes says. Since then, the district has seen performance gains in data availability for its student management system. The SAN also lets Holmes and his staff perform live maintenance during the day without endangering systems or shutting them down.

The district has deployed two blade clusters attached to the SAN, with the configuration taking minutes rather than hours to implement as it had with direct-attached storage, Holmes says. AMSD plans to connect two more server clusters to the SAN in the coming months and expects to see the break-even point for its investment within the year, he says.

Control Operations Costs

Albuquerque Public Schools has deployed a SAN for many years, though its NetApp FAS3020C has been largely dedicated to the district's Microsoft Exchange e-mail messaging system, says Dale Alexander, director of core technologies and communications. Late last year, APS refreshed its SAN technology with the installation of an iSCSI NetApp FAS3140A and will repurpose the older SAN for disaster recovery.

The reliability of the NetApp SAN, along with ease of management and vendor support when problems arise, are primary advantages over other kinds of storage, says Alexander. The SAN will also facilitate planned virtualization initiatives within the district, he says.

With about 40,000 computing devices distributed among the more than 140 schools in the system, APS is moving toward a centralized storage architecture in order to use capacity more efficiently, Alexander says.

“We had a very distributed model in the district, but we're trying now to pull the storage together to use it more efficiently and to take over the administrative burden from the individual schools,” he says.

Carbon-Lehigh Intermediate Unit 21, which provides educational and technology services for 14 school districts as well as vocational schools in two eastern Pennsylvania counties, installed a Fibre Channel SAN with a Brocade switch in 2002, says Philip Fiore, assistant director of management information services.

The agency moved to a SAN when it became clear that new applications (such as streaming audio and video) and mounting volumes of data were raising the cost of technology services and pushing the limits of existing local storage technologies, Fiore says.

“The data stored on the SAN is absolutely crucial to the services we provide to our constituent schools, such as e-mail, student and financial information,” Fiore adds. “Our school districts rely on technology just as much as businesses do, and the SAN provides us with high availability and redundancy to meet their needs.”