NAS remains simple and cost-effective

One distinction between a NAS device and a traditional file server is the operating system. Traditional file servers use Novell NetWare, Linux, OS/2, Windows or Unix to offer file-based services out to the network. But file servers have other modules, code and features that do not directly relate to serving files. Because a NAS device is tuned for a specific function, it lacks other features, such as an application server or a directory server.
But even though NAS devices lack such features, NAS continues to gain in popularity because users like the concept of just plugging a device into their Ethernet network and having storage available a few minutes later. Companies such as NetApp and Snap Server by Adaptec took this one step further and created an "enterprise NAS" device, elevating NAS to a powerhouse of centralized file serving. An enterprise NAS uses external disk shelves, each containing 10 to 14 disks.
NAS systems have a credible, full-featured, performance-tuned operating environment and software stack geared toward serving up files to your networked computers. These systems also have features that allow non-Windows computers to attach to the shares like NFS and have added more and bigger networking ports, block-based storage, and 2 Gbps and 4 Gbps Fibre Channel interconnects.
Even though NAS is relatively easy to implement, storage administrator still need a healthy knowledge of the various NAS components, such as NAS interconnects, as well as NAS protocols. And with tight budgets all around, it's only prudent to make sure you get the biggest bang for your storage buck. Document what you need, plan ahead and build a solid RFP to present to the NAS vendors.