NAS spells relief from storage woes

The scenario is all too familiar to network administrators: Your network file servers are running out of storage space, and you can't think of any more quick fixes for the problem.You could ask all users on the network to delete their unused files, but this is a temporary solution at best. So is installing extra hard drives into your PC server'which also costs you in labor and downtime while the server is offline.Buying another server is an expensive solution, too, especially when you consider the cost of per-seat operating licenses and the time it takes to install and configure.But before you give up, here's another option: network-attached storage, or NAS.NAS servers are single-purpose appliances dedicated to serving files. Most of the products listed in this roundup are suited for workgroup and small department use.All NAS servers connect directly to the network; hence the term 'network-attached.' They don't replace PC servers; they work independently to provide a simple, cost-effective answer to network storage problems.Traditional PC servers are very good at handling multiple tasks, but they are overbuilt for the relatively simple task of file sharing. In addition, an OS licensing fee is required for each client they serve.NAS servers are built from the outset as file servers. To save on initial costs, they do away with nonessential components such as mice, monitors and keyboards. The specialized OSes used by NAS servers are generally embedded into the server, so they don't require licensing fees. And NAS server OS upgrades usually are free via a Web download.In most workgroup environments, there is a mix of Windows, Macintosh, Unix and Linux clients that need support for a variety of network protocols. NAS servers are typically configured with built-in network protocols that make them appear to users as native file servers.As with other emerging technologies, new uses for NAS servers are being discovered all the time, according to leading vendors.In workgroups, NAS servers holding large files are placed nearest the groups of users that most frequently access them. This helps isolate network traffic and assists with network and server load balancing, according to a white paper from Snap Appliances Inc.Frequently used software configurations can be duplicated and distributed on NAS servers throughout the organization; a move that takes the load off the primary file servers.NAS servers also provide an inexpensive solution for archiving computer-aided design and other data-intensive files.The latest versions of application software can be easily downloaded from NAS servers by traveling employees who attach their notebook computers to the network, ensuring that everybody in the organization is using supported software versions.They are easy to install and administer and offer better price per performance than general-purpose servers, making NAS servers ideally suited for Internet and intranet operations, ISP hosting, e-commerce, Web filer needs, departmental data servers and virtually any distributed file or data sharing applications, according to another NAS manufacturer, Emerging Systems Inc.Which features are most important? What benefits should you expect? The following criteria, while not all-inclusive, will get you started on the road to finding the NAS server that's best for your organization.Easy installation. Because they provide a relatively limited set of functions, NAS servers ought to be plug-and-play devices, installed and integrated into a network within minutes.Cross-platform file sharing. Host systems that access and share data stored on NAS appliances can run different OSes. The most commonly used are the Unix Network File System, Windows Common Internet File Service, Apple Inc.'s Apple Filing Protocol, Novell Inc.'s NetWare Core Protocol and HTTP for the Web.Scalability. In NAS storage architectures, several servers can be added to a single network. Most NAS vendors offer a family of products, ranging from small, single-drive servers to high-end products with multiple disk drives in a rackmount chassis. The products listed in the accompanying chart are samples of what each vendor offers.Configuration. Some vendors provide servers in rackmount, tower or desktop configuration. Rackmount NAS servers generally scale more easily than do tower servers, at least at the entry and midrange service levels.Network options. Most midrange NAS servers come with one or two 10/100-Mbps Ethernet connections. Some come with additional options, such as 10/100/1000-Mbps Gigabit or Fiber Gigabit connections.Web-based and SNMP management. Because they're specialized, NAS servers don't require the same level of maintenance as general-purpose PC servers do. Most routine maintenance can be performed via a Web browser from any client or workstation on the Internet. The Simple Network Management Protocol should be built-in to help manage the servers across the network.Performance under load. Data throughput under load'that is, when processing a high number of transactions'is an important measure of any file server. The NAS server manufacturer will provide information; independent lab tests are also a good source. Depending on the type of connection, the NAS server should be able to serve many users concurrently without performance degradation.