For many CIOs, the limitations of conventional NAS systems are a nonissue because their applications fall well below those thresholds. Other factors are more important, including ease-of-use and the ability to consolidate data from multiple applications into a single repository -- and not necessarily a single file system.

Cost is also an important aspect. "What drives most of these decisions nowadays is the financial aspect," says Glen Duzy Sr., a consultant at GlassHouse Technologies. "The desire to save money can bring [customers] toward the appliance model. Most of the commercial accounts are more concerned about the operational cost and the availability."

An interesting example of how adopting a traditional SAN plus NAS can save the day comes from Jerome Waldron, CIO of Salisbury University in Salisbury, Md. SU is a midsize university, Waldron explains, lacking perhaps the financial and technical resources of larger institutions, but with an equally sophisticated set of requirements to serve its personnel and 7,000 students.

SU's IT department was facing some serious challenges, including migrating from old applications to PeopleSoft, managing an exploding volume of e-mail messages, and managing daily tape backups.

"We had to move away from tape," Waldron says, explaining that there weren't enough hours in a day to perform tape backups for the university's roughly 100 servers.