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NAS is not all that novel a concept and, unlike SANs, is the end result of other products' evolution. NAS boxes first appeared a few years ago as big bulky NFS (Network File System) file servers that were expensive, lacked functionality and provided a clumsy interface. In short, they completely undermined the utility they were designed to provide. Despite their underwhelming debut, NAS servers have improved and are now hogging the limelight in the storage arena.

Today, these servers have sufficiently matured to be considered a viable solution in any production network. Currently, there are three basic types of NAS servers: hard disk, optical disk and tape backup. A NAS server can consist of any number of permutations of these three storage media types.

The NAS Players
Now that NAS solutions have become a hot topic, the permutations are rapidly evolving further. In our quest to track down servers for our RAID-based NAS server tests, we quickly realized just how fast the NAS market is moving, with vendors updating their products as we were testing. In fact, much to our dismay, many vendors, including Hewlett-Packard Co., declined to submit products, explaining that their products wouldn't be available until the second half of this year. Land-5 Corp. told us that its current NAS product was undergoing a redesign and that it would prefer not to submit a first-generation box.

Still, when all was said and done, we ended up with four very different systems to test, which provided us a good representation of both workgroup and enterprise-class servers.

In our Real-World Labs® at the University of Wisconsin-Madison, we tested four servers: Network Appliance's NetApp F760 Enterprise, LSI Storage Systems' LSI Logic MetaStor SH850, Meridian Data's Snap, and Cobalt Networks' NASRaQ. Because the servers varied so significantly, an apples-to-apples comparison was impossible. Instead, we took a look at the server pieces in order to use them as reference points for the NAS market. This let us examine two segments of the NAS market and develop a frame of reference for future products.

We put the servers through a series of tests to highlight performance, which is a very important factor when considering NAS servers. For our testing procedure, we used Coffee Computing's FileMetric version 1.2. FileMetric is a client/server-based benchmark that runs a multithreaded client on each of the host machines, while a remote console is used to initiate and configure the hosts.

Our NAS benchmarks consist of a suite of six distinct scripts that perform cached and uncached random reads and writes as well as simulated client application launching and severe server I/O environments. We used 10 to 25 clients ranging from Pentium 200s to quad Pentium IIIs.

Because there was a clear discrepancy in both price and performance across the different servers, we divided them into two groups based on price range: The Network Appliance F760 and the MetaStor SH850 comprised the enterprise/departmental group; the Cobalt NASRaQ and Meridian Data Snap server were earmarked for the workgroup.

Note that the MetaStor NAS is not directly positioned at the enterprise market and that LSI markets two other servers above it in its product line. However, the device we tested is relatively close in price to the F760. In the end, the Network Appliance F760 received our Editor's Choice award for its stellar performance, excellent scalability and reasonable price. Meridian Data's Snap server received our Best Value award for its ability to deliver exceptional performance at a rock-bottom price.