(1) See network access server.

(2) (Network Attached Storage) A specialized file server that connects to the network. A NAS device contains a slimmed-down operating system and a file system and processes only I/O requests by supporting the popular file sharing protocols, primarily CIFS for Windows and NFS for Unix.

     The NAS concept originated in the early 1990s for computer-aided-design (CAD) and other applications that generated huge data files. File servers with full-blown operating systems have sometimes been called network attached storage, but a true NAS can perform no task other than I/O.

Just Plug It In
Using traditional LAN protocols such as TCP/IP over Ethernet, the NAS enables additional storage to be quickly added by plugging it into a network hub or switch. As network transmission rates have increased from Ethernet to Fast Ethernet to Gigabit Ethernet, NAS devices have come up to speed parity with direct attached storage devices. See NAS gateway, SAN and NetApp Filer.












Industrial Strength NAS
Network Appliance popularized the network attached storage (NAS) device. Sophisticated units such as this one can hold terabytes of storage and provide mission critical reliability for large enterprises. (Image courtesy of Network Appliance, Inc.)





SOHO and Personal Use
In 2002, Iomega introduced a line of economical RAID-based NAS devices with capacities to 480GB. Suited to the individual or small to medium-sized LAN, this model had a hot spare ready to replace a failed drive. (Image courtesy of Iomega Corporation.)