RFC 1094 (rfc1094) - Page 1 of 27

NFS: Network File System Protocol specification

Alternative Format: Original Text Document

Network Working Group                             Sun Microsystems, Inc.
Request for Comments: 1094                                    March 1989

            NFS: Network File System Protocol Specification


   This RFC describes a protocol that Sun Microsystems, Inc., and others
   are using.  A new version of the protocol is under development, but
   others may benefit from the descriptions of the current protocol, and
   discussion of some of the design issues.  Distribution of this memo
   is unlimited.


   The Sun Network Filesystem (NFS) protocol provides transparent remote
   access to shared files across networks.  The NFS protocol is designed
   to be portable across different machines, operating systems, network
   architectures, and transport protocols.  This portability is achieved
   through the use of Remote Procedure Call (RPC) primitives built on
   top of an eXternal Data Representation (XDR).  Implementations
   already exist for a variety of machines, from personal computers to

   The supporting mount protocol allows the server to hand out remote
   access privileges to a restricted set of clients.  It performs the
   operating system-specific functions that allow, for example, to
   attach remote directory trees to some local file system.

1.1.  Remote Procedure Call

   Sun's Remote Procedure Call specification provides a procedure-
   oriented interface to remote services.  Each server supplies a
   "program" that is a set of procedures.  NFS is one such program.  The
   combination of host address, program number, and procedure number
   specifies one remote procedure.  A goal of NFS was to not require any
   specific level of reliability from its lower levels, so it could
   potentially be used on many underlying transport protocols, or even
   another remote procedure call implementation.  For ease of
   discussion, the rest of this document will assume NFS is implemented
   on top of Sun RPC, described in  RFC 1057, "RPC: Remote Procedure
   Call Protocol Specification".

1.2.  External Data Representation

   The eXternal Data Representation (XDR) standard provides a common way
   of representing a set of data types over a network.  The NFS Protocol

Sun Microsystems, Inc.