Technical data

21
NFS Client
The Network File System (NFS) client software enables client users to access file
systems made available by an NFS server. These files and directories physically
reside on the remote (server) host but appear to the client as if they were on the
local system. For example, any files accessed by an OpenVMS client — even a
UNIX file — appear to be OpenVMS files and have typical OpenVMS file names.
This chapter reviews key concepts and describes:
• How to start up and shut down the NFS client (Section 21.2)
• How to register users in the proxy database (Section 21.3)
• How to mount files and directories (Section 21.4)
For information about the NFS server, see Chapter 20.
21.1 Key Concepts
Because the NFS software was originally developed on and used for UNIX
machines, NFS implementations use UNIX file system conventions and
characteristics. This means that the rules and conventions that apply to
UNIX file types, file names, file ownership, and user identification also apply to
NFS.
Because the TCP/IP Services NFS client runs on OpenVMS, the client must
accommodate the differences between the two file systems, for example, by
converting file names and mapping file ownership information. You must
understand these differences to configure NFS properly and to successfully mount
file systems from an NFS server.
The following sections serve as a review only. If you are not familiar with these
topics, see the DIGITAL TCP/IP Services for OpenVMS Concepts and Planning
guide for a more detailed discussion of the NFS implementation available with
the TCP/IP Services software.
21.1.1 NFS Clients and Servers
NFS is a client/server environment that allows computers to share disk space and
users to work with their files from multiple computers without copying them to
the local system. Computers that make files available to remote users are NFS
servers. Computers with local users accessing and creating remote files are NFS
clients. A computer can be an NFS server or an NFS client, or both a server and
a client.
Attaching a remote directory to the local file system is called mounting a
directory. A directory cannot be mounted unless it is first exported by an NFS
server. The NFS client identifies each file system by the name of its mount point
on the server. The mount point is the name of the device or directory at the top
of the file system hierarchy. An NFS device is always named DNFSn.
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