File Systems Boost NAS

Virtual file systems offer more than global namespace and unified management of storage networking gear. They actually improve its performance.

Though NAS vendors might downplay their role as throughput helpers, suppliers like Acopia Networks Inc., NeoPath Networks, NuView Inc., Rainfinity, and others are helping customers avoid bottlenecks.

Ibis Consulting, for instance, is using Acopia's ARX switches with two BlueArc Corp. Titan NAS systems to help avoid performance problems. Ibis analyzes and transfers huge amounts of electronic data required in legal proceedings.

During the legal discovery process, as information is added to a client's file, Ibis's 150-plus servers might clamor for a "share" or portion of space on a disk in the NAS all at once, causing throughput to slow.

"We collect multiple-terabyte data sets. If we get a particularly large data set, it can physically create a bottleneck," says Ibis CTO Cliff Dutton. He won't quantify the performance lag, but says that adding Acopia headed off a significant potential problem.This isn't to point fingers at BlueArc, Dutton maintains. Indeed, BlueArc claims to handle file sizes up to 256 Tbytes per filer. The problem is "hot spots" on the NAS, where multiple requests hit a single processor inside the machine. Acopia's switch spreads the load more evenly across the arrays and keeps performance balanced.

The Acopia switch also does its allocation automatically. Before Acopia, files could be assigned to separate volumes on the NAS filers, Dutton says. But that required operators to manually change the storage configuration -- no go from a cost-and-efficiency perspective.

BlueArc spokespeople acknowledge Acopia's role as a partner in several customer implementations, but the NAS vendor downplays the performance issue. Acopia's main contribution, according to BlueArc director of marketing Jim Schaff, is to offer a global namespace for customers who adopt BlueArc NAS alongside older gear, or to manage NAS space more efficiently. The use of Acopia for load balancing is rare, he says.

At least one other vendor supports this view. "The percentage of customers using our products for NAS performance is very minute," says Rahul Mehta, founder at CEO at NuView. Over 300 customers are now using NuView's products, he says.

At least one analyst says this kind of deployment is "bleeding edge," but it's likely to keep happening, particularly at the high end. "I think we'll begin to see network file management increasingly in front of high-end NAS," says Brad O'Neill, senior analyst at the Taneja Group. While it's not clear how EMC or Network Appliance Inc. (Nasdaq: NTAP) plan to face the issue, he says, they'll eventually have to do so. "It's too obvious and easy a benefit to gain. A lot of things will change as a result of this."Mary Jander, Site Editor, Byte and Switch