Network File System

Network File System (NFS) is a distributed file system protocol originally developed by Sun Microsystems (Sun) in 1984, allowing a user on a client computer to access files over a computer network much like local storage is accessed.

Sun Microsystems, Inc. (Sun for short) was an American company that sold computers, computer components, software, and information technology services and created the Java programming language, the Solaris operating system, ZFS, the Network File System (NFS), and SPARC.

Network File System (NFS) is a distributed file system protocol originally developed by Sun Microsystems (Sun) in 1984, allowing a user on a client computer to access files over a computer network much like local storage is accessed.

In 1985 Sun Microsystems created the file system called "Network File System" (NFS) which became the first widely used Internet Protocol based network file system.

Version 2 of the protocol (defined in RFC 1094, March 1989) originally operated only over User Datagram Protocol (UDP).

The Virtual File System interface allows a modular implementation, reflected in a simple protocol.

It allowed Unix system calls to access local UFS file systems and remote NFS file systems transparently.

WebNFS, an extension to Version 2 and Version 3, allows NFS to integrate more easily into Web-browsers and to enable operation through firewalls.

WebNFS is an extension to the Network File System (NFS) for allowing clients to access a file system over the internet using a simplified, firewall-friendly protocol.

People involved in the creation of NFS version 2 include Russel Sandberg, Bob Lyon, Bill Joy, Steve Kleiman, and others.

At Sun, Joy was an inspiration for the development of NFS, the SPARC microprocessors, the Java programming language, Jini/JavaSpaces, and JXTA.

Alternative remote file access protocols include the Server Message Block (SMB, also termed CIFS), Apple Filing Protocol (AFP), NetWare Core Protocol (NCP), and OS/400 File Server file system (QFileSvr.400).

In macOS, AFP is one of several file services supported, with others including Server Message Block (SMB), Network File System (NFS), File Transfer Protocol (FTP), and WebDAV.

Version 4 (RFC 3010, December 2000; revised in RFC 3530, April 2003 and again in RFC 7530, March 2015), influenced by Andrew File System (AFS) and Server Message Block (SMB, also termed CIFS), includes performance improvements, mandates strong security, and introduces a stateful protocol.

The Andrew File System heavily influenced Version 4 of Sun Microsystems' popular Network File System (NFS).

NFS is often used with Unix operating systems (such as Solaris, AIX, HP-UX), Apple's macOS, and Unix-like operating systems (such as Linux and FreeBSD).

AIX v2 included full TCP/IP networking, as well as SNA and two networking file systems: NFS, licensed from Sun Microsystems, and Distributed Services (DS).

Some file systems are used on local data storage devices; others provide file access via a network protocol (for example, NFS, SMB, or 9P clients).

NFS, like many other protocols, builds on the Open Network Computing Remote Procedure Call (ONC RPC) system.

ONC was originally developed by Sun Microsystems in the 1980s as part of their Network File System project, and is sometimes referred to as Sun RPC.

NFS is often used with Unix operating systems (such as Solaris, AIX, HP-UX), Apple's macOS, and Unix-like operating systems (such as Linux and FreeBSD).

Whether and how locks work on network filesystems, such as NFS, is implementation dependent.

Arguments focused on the method for data-encoding — ONC's External Data Representation (XDR) always rendered integers in big-endian order, even if both peers of the connection had little-endian machine-architectures, whereas NCS's method attempted to avoid byte-swap whenever two peers shared a common endianness in their machine-architectures.

NFS is often used with Unix operating systems (such as Solaris, AIX, HP-UX), Apple's macOS, and Unix-like operating systems (such as Linux and FreeBSD).

Ironically, Sun and AT&T had formerly competed over Sun's NFS versus AT&T's Remote File System (RFS), and the quick adoption of NFS over RFS by Digital Equipment, HP, IBM, and many other computer vendors tipped the majority of users in favor of NFS.

It was also included in UNIX System V Release 4, but as that also included the Network File System (NFS) which was based on TCP/IP and more widely supported in the computing industry, RFS was little used.

In January, 2010, Panasas proposed an NFSv4.1 based on their Parallel NFS (pNFS) technology claiming to improve data-access parallelism capability.

Panasas developed an extension for managing parallel file access in the Network File System, which was later integrated in Parallel NFS (pNFS), part of the NFS version 4.1 specification, published by the Internet Engineering Task Force as RFC 5661 in January 2010.

Many of them, for example AIX, FreeBSD, Mac OS X beginning with version 10.4 ("Tiger"), or Solaris with ZFS filesystem, support NFSv4 ACLs, which are part of the NFSv4 standard.

It is also available to operating systems such as Acorn RISC OS, AmigaOS, the classic Mac OS, OpenVMS, MS-DOS, Microsoft Windows, Novell NetWare, and IBM AS/400.

One noteworthy benchmark pitted NetWare 3.x running NFS services over TCP/IP (not NetWare's native IPX protocol) against a dedicated Auspex NFS server and a SCO Unix server running NFS service.

Note that automation of the NFS mounting process may take place — perhaps using and/or automounting facilities.

The first Unix CacheFS implementation was developed by Sun Microsystems and released in the Solaris 2.3 operating system release in 1993, as part of an expanded feature set for the NFS or Network File System suite known as Open Network Computing Plus (ONC+).

It is primarily a feature of NFS but may be available on other systems as well.

For distributed remote file systems with multiple users, protocols such as Apple Filing Protocol, Network File System and Server Message Block are more often used.