NFS Services Administrator's Guide

Introduction
ONC Services Overview
Chapter 1 17
ONC Services Overview
Open Network Computing (ONC) services is a technology that consists of
core services which enable you to implement distributed applications in a
heterogeneous, distributed computing environment. ONC also includes
tools to administer clients and servers.
ONC services consists of the following components:
• Network File System (NFS) enables you to access files from any
location on the network, transparently. An NFS server makes a
directory available to other hosts on the network, by sharing the
directory. An NFS client accesses the shared directories on the NFS
server by mounting the directories. For users on the NFS client, the
directories appear as a part of the local filesystem. For information
on configuring and administering NFS, see Chapter 2, “Configuring
and Administering NFS Services,” on page 41.
• AutoFS is a client-side service that automatically mounts and
unmounts filesystems, transparently. AutoFS performs automatic
mounting and unmounting by instructing the user-space daemon,
automountd, to mount and unmount the directories it manages. For
information on configuring and administering AutoFS, see
“Configuring and Administering AutoFS” on page 99.
• CacheFS is a general purpose filesystem caching mechanism that
can improve the NFS server performance scalability by reducing
server and network load. For information on configuring and
administering a cache filesystem, see “Configuring and
Administering a Cache Filesystem” on page 147.
• Network Lock Manager (NLM) and Network Status Monitor
(rpc.lockd and rpc.statd) provide file locking and synchronized file
access to files that are shared using NFSv2 or NFSv3. File locking
with NFSv2 and NFSv3 is advisory only. The rpc.lockd daemon
starts the kernel KLM server. The rpc.statd daemon implements a
lock recovery service used by KLM. It enables rpc.lockd daemon to
recover locks after the NFS service restarts.
Files can be locked using the lockf() or fcntl() system calls. For
more information on daemons and system calls that enable you to
lock and synchronize your files, see lockd (1M), statd (1M), lockf (2),
and fcntl (2).