Managing Systems and Workgroups: A Guide for HP-UX System Administrators

Setting Up and Administering an HP-UX NFS Diskless Cluster
What Is an NFS Diskless Cluster?
Chapter 10 899
What Is an NFS Diskless Cluster?
An HP-UX NFS diskless cluster is a network of HP 9000 Series 700
and 800 computers sharing resources, particularly operating systems
and file system elements. The underlying technology is the Network File
System (NFS) and its protocols.
The NFS diskless cluster consists of a cluster server (sometimes
referred to simply as the server) and one or more cluster clients all
attached to a network. Each computer in the cluster (including the
cluster server) is referred to as a cluster node or cluster member.
HP-UX releases 10.0 through 10.20 support diskless clusters that have
Series 700 or 800 cluster servers and Series 700 cluster clients.
NOTE The term “diskless” refers to the fact that client systems do not need a
local file system device to boot and run. The specific feature of an HP-UX
NFS diskless cluster is that the clients boot and load their operating
systems from the cluster server and establish their root file systems from
the cluster server. Diskless client systems can still have disks and other
peripherals directly attached to them.
The cluster server provides the facilities needed for clients to boot over
the network from kernels residing in the cluster server’s file system.
Because a cluster client has no local root file system, the server provides
a root file system to the client. By default, clients swap to storage space
on the server. If a client has its own disk, the disk can be used for a local
file system, for swap/dump, or for both.
A cluster can be administered as a single system, as a group of individual
systems, or as a system in which some resources are shared and others
are not. The behavior of the system and its appearance to the user and
administrator depend on the sharing policies selected (see “Planning
Your Cluster Policies” on page 902) and the use of cluster-wide resources.
More detailed information on NFS diskless clusters is available in the
NFS Diskless Concepts and Administration White Paper. This document
also compares NFS diskless clusters with the HP-proprietary “DUX”
clustered environment that was available in software releases preceding
release 10.0. The white paper is available on most 10.x systems in