Network File System (NFS) is a protocol originally developed by Sun Microsystems in 1984 and defined in RFC 1094, 1813, (3010) and 3530, as a file system which allows a computer to access files over a network as if they were on its local disks.

Versions 2 and 3 of the protocol used the User Datagram Protocol (UDP) and were meant to keep the protocol stateless, with locking (for example) implemented outside of the core protocol. Version 4 includes performance improvements and introduces a stateful protocol. It has thus been possible to use NFS over TCP since version 3.

NFS is strongly associated with UNIX systems, though it can be used on any platform such as Macintosh and Microsoft Windows operating systems. The server message block (SMB), a similar protocol, is the equivalent implementation of a network file system under Microsoft Windows.

The term "network file system" is also often used as a generic term — see file system for other examples.

External links

• RFC 3530 - NFS Version 4 Protocol Specification
• RFC 1813 - NFS Version 3 Protocol Specification
• RFC 1094 - NFS Version 2 Protocol Specification