Open System Services NFS Management and Operations Guide

1 Introduction to OSS NFS
This chapter describes the components of the OSS NFS subsystem, lists the services provided, and
details the various protocols and interfaces supported. It presents an external view of the OSS NFS
subsystem in relation to the operating system and its data communications subsystems. Throughout
this manual, the term operating system refers to the HP NonStop operating system.
Overview
The OSS NFS subsystem provides transparent, remote access to file systems on NonStop systems.
It allows clients (computers running NFS version 2 client software) to access files held in reliable,
expandable storage on NonStop systems.
OSS NFS Conformance
OSS NFS is based on these X/Open NFS protocols:
• NFS
• Mount
• Port mapper
• PCNFSD
OSS NFS software also conforms to a number of Requests for Comments (RFCs) maintained by the
Defense Data Network (DDN) at the DDN Network Information Center (NIC). These RFCs define
the various protocols implemented by the OSS NFS software.
NFS Protocol
The NFS protocol implements a remote file system based on the Sun Microsystems, Inc. Network
File System (NFS) as defined by RFC 1094. This protocol is independent of the system, operating
system, network architecture, and transport protocol. This independence is achieved by using
Remote Procedure Call (RPC) primitives and an external data representation (XDR).
OSS NFS provides transparent remote access to NonStop system files through the NFS protocol
version 2 based on the X/Open XNFS document. The NFS protocol is supported only for User
Datagram Protocol (UDP) clients. The OSS NFS pathnames follow UNIX syntax rules. For more
information on the NFS protocol, see the Open System Services NFS Overview.
Remote Procedure Call (RPC)
From a server, RPC provides a standard way to invoke services on another (remote) server that is
linked to the first one by a network. The RPC specification is defined by RFC 1057. Each server
supplies a program that responds to these calls; NFS is one such program. The combination of
host address, program number, and procedure number specifies one remote service procedure.
RPC does not depend on specific transport protocols, so it can be used with any underlying protocol.
For more information on the RPC protocol, see the NFS protocol description in the Open System
Services NFS Overview.
External Data Representation (XDR)
NFS uses the external data representation (XDR) standard, defined by RFC 1014. For more
information on this protocol, see the Open System Services NFS Overview.
Mount Protocol
OSS NFS clients use the mount protocol specified in the X/Open XNFS document to establish
access to an OSS NFS server. It is supported only for UDP clients.
14 Introduction to OSS NFS