NFS Services Administrator's Guide (5900-1632, August 2011)

1 Introduction
This chapter introduces the Open Network Computing (ONC) services, such as NFS, AutoFS, and
CacheFS.
This chapter addresses the following topics:
• “ONC Services Overview” (page 9)
• “Network File System (NFS)” (page 9)
• “New Features in NFS” (page 10)
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” (page 17).
• 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” (page 47).
• 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”
(page 79).
• 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).
• Remote Procedure Call (RPC) is a mechanism that enables a client application to communicate
with a server application. The NFS protocol uses RPC to communicate between NFS clients
and NFS servers. You can write your own RPC applications using rpcgen, an RPC compiler
that simplifies RPC programming. Transport-Independent RPC (TI-RPC) is supported on HP-UX
11i v3. For information on RPC, see rpc(3N) and rpcgen(1). For more information on RPC
and rpcgen, see John Bloomer, Power Programming with RPC.
Network File System (NFS)
The Network File System (NFS) is a distributed filesystem that provides transparent access to files
and directories that are shared by remote systems. It enables you to centralize the administration
of these files and directories. NFS provides a single copy of the directory that can be shared by
ONC Services Overview 9