NAS Provides Painless Way to Add Storage

In most IT organizations, information glut has created the need for extensible storage devices that can scale in response to the dynamic and rapidly changing needs of enterprise environments.

With the development of a theoretically plug-and-play Network-Attached Storage (NAS) paradigm, storage vendors may finally have given IT managers a much needed weapon in their struggle against information glut. AS/400 managers with Windows NT in their environments can leverage NAS solutions through the Windows NT operating system, thus providing a relatively painless method of adding storage as rapidly expanding data requirements dictate.

In the most basic sense, NAS is storage connected directly to the network without the intervention of a physical host or interface. AS/400 managers can plug NAS solutions anywhere into their Windows NT-, Novell- or Unix-based networks, without the intervention of a controlling host or operating system.

“Network Attached Storage (NAS) is the ability to attach storage directly to the network, typically without the intervention of some type of host,” explains Kevin Liebl, a product manager with storage vendor MTI Technology Corp. (Anaheim, Calif.). “In other words, you have direct-attached storage, where the storage subsystem is attached directly to the host via SCSI or FC and then you have NAS where the storage attaches to the network without attaching to a host. The benefit is the ability to share the storage by all servers/workstations on the network.”According to Farid Neema, president of Peripheral Concepts Inc., a Santa Barbara, Calif.-based IT consultancy, and the individual first credited with coining the term “Network Attached Storage,” NAS differs fundamentally from other storage paradigms.

“The most commonly known storage today is directly attached to a server and the server itself is attached to a network,” Neema explains. “The difference with NAS is that rather than being attached to a server, the storage is directly connected to a LAN itself, and whatever protocol is required to interface with the network is included in the NAS.”

And rather than being connected via channel or bus to a conventional operating system, NAS is an autonomous network entity, says Jonathan Otis, director of product management with storage and tape library vendor Advanced Digital Information Corp. (Redmond, Wash.). “NAS is anything attached to the network that is not Unix, NT or NetWare; that’s how broad it is,” he observes. “It’s peripherals and subsystems and application servers that are running on nonstandard operating systems.”

Simply put, NAS products attach directly to LANs and communicate using NFS, CIFS, FTP, HTTP and other networking protocols. NAS devices can be implemented across any number of network topologies, including Ethernet, Fast (or Gigabit) Ethernet, ATM and even Fibre Channel. NAS devices may even emulate conventional network file servers.In the NAS paradigm, the file system is integrated directly into the operating system or real-time operating system of the NAS device itself.

NAS acceptance enjoyed a gradual ramp-up over 1998, and now vendors are applying the technology to additional market segments, including printers and CD-ROM servers. For example, Creative Design Solutions Inc. (Santa Clara, Calif.) -- manufacturer of the Plug and Stor line of thin server products -- is incorporating NAS function into not only conventional storage media, but also into printers, disk drives and CD-ROM drives.

Not surprisingly, NAS is seeing its greatest growth in the Windows NT space, as it provides a relatively transparent means of augmenting network storage capabilities. Even for AS/400 managers relatively new to the Windows NT operating system, NAS solutions should prove to be essentially plug-and-play.