Buyer's Guide: Network Attached Storage

So your organization is straining under the burden of a burgeoning data load and you need somewhere to store the stuff? Adding servers would address the ailment, but it's too rich a solution for your budget. The prescription for those woes may just be network attached storage (NAS).

NAS devices differ from servers in several ways that make them more economical to buy. Think of an NAS device as storage-centric compared to servers which are application-centric. Another way to look at NAS hardware is that, unlike a server which is a general-purpose computer dedicated to storage tasks, an NAS device is purpose-built around hardware for storage and file transfers.

Buffalo TeraStation ES

NAS appliances can be either free-standing or rackmounted. They don't need keyboards or monitors. They're usually controlled by a network interface. Rather than using a full-blown operating system, they typically have an embedded OS, which can be proprietary or a version of a popular system optimized for storage tasks.

Any data stored in files -- e-mail, databases, Web content, system backups and such -- can be filed on the appliance's storage components. Those components can be any number of drives, including tape drives. The drives are connected to what's called an NAS head or gateway. Clients on the network do not have direct access to the drives. They must go through the head to interact with them.

Because a NAS device is a prepackaged server optimized for storage it has certain advantages. For example, it's designed to be a plug-and-play device. Its hallmarks are ease of use, facile installation, breezy management over the network -- often through a Web browser -- and solid security. The browser interface can be especially useful if it allows you to handle network file system (NFS) tasks through the NAS system because it reduces the need for administrators to have extensive NFS skills. In general, the rule of thumb is, if it takes as long to set up a NAS appliance as it does to configure a server with storage, then that's a NAS appliance to be avoided.

Market Segments

Typically, NAS appliances fall into three categories. At the low end, there are devices with one to five terabytes of storage that sell for under $1,000 that may be suitable for a workgroup, home office, or small office. Offerings like the Buffalo TeraStation ES ($650-$1,400), which has four 500GB hot-swappable drives and RAID support, and the LaCie 5big Network ($800), with five 1TB hot-swappable drives and RAID support, fall into this category.

Midrange NAS devices fall into the $2,000 to $3,000 price range and can meet the needs of small and medium-sized businesses. The Overland Storage Snap Server 410 ($2,600), with RAID support and accommodations for four 2TB hot-swappable drives running GuardianOS, falls into the group, as does the Netgear ReadyNAS NVX RNDX4420 ($2,300-$3,900), with four 2TB hot-swappable drives, RAID support, Gigabit Ethernet and running the RAIDiator OS.

Boxes selling above $3,000 are the meat of the NAS market for midsized firms and the enterprise. NAS appliances in this realm range from HP's StorageWorks Network Storage System X1400 ($3,500-$5,000) to the Quantum DXi6520 NAS ($64,000).

Iomega StorCenter ix12-300r

Which OS?

How do you know if a NAS appliance will fit your needs? If you want to get a shared storage solution online quickly, then NAS may be for you. It's also a good solution if you need to consolidate your file and print servers to optimize the capacity utilization and performance of your network. If you have to deal with diminishing human resources or greater demands on existing staff, NAS can help reduce the time dedicated to managing and securing your data. NAS is also a viable solution for providing a disk-based alternative to tape storage or an intermediate tier before writing to tape.

Maintenance and complexity can also be reduced with NAS. Because many of the capabilities built into a server -- applications, services and hardware peripherals -- have been stripped from the NAS device, it tends to be less susceptible to system crashes and security attacks. Even when something does go wrong with the NAS, its reduced complexity makes it easier to diagnose the problem and to get the hardware back up and running.

Sometimes NAS device makers will hide the operating system personality of their appliances. That allows your users to access the devices with clients that aren't wedded to any particular operating system -- which may be handy on a mixed-platform network. If you do have a mixed environment, you should make sure that a prospective NAS device supports protocols for clients running on popular operating systems like Windows, Linux, Unix, OS X, and NetWare. If the device does support a range of protocols, you should make sure there are no hidden licensing fees for using them. Native support of HTTP and FTP on a NAS appliance is useful, too.

There are advantages, however, to deploying an NAS system with a less agnostic operating system. For example, if you're a pure Windows shop, deploying a NAS device using Windows Storage Server 2008, which is optimized for maximized storage performance and simplified management, may smooth integration with your existing Windows hardware. It will also let you take advantage of your existing administrators' knowledge of Windows. Training personnel in the intricacies of an alien operating system only adds to the total cost of ownership for the new appliance.