HP-UX System Administrator's Guide: Overview

• Serviceguard Clusters
• Extended Campus / Extended Distance Clusters
• Metropolitan Clusters
• Continental Clusters
Serviceguard
A Serviceguard cluster is a networked group of HP Integrity or HP 9000 servers (known
to Serviceguard as nodes) having sufficient redundancy of software and hardware that
a single point of failure will not significantly disrupt service. The ability to continue
operating in spite of a software or hardware failure makes Serviceguard clusters highly
available.
Technology Summary
When you configure a Serviceguard cluster, you set up as many redundancies as
possible, both in hardware and software. To provide the greatest degree of availability,
Serviceguard typically works in conjunction with other high availability products such
as:
• MirrorDisk/UX
• VERITAS Volume Manager (VxVM)
• Disk arrays using various RAID levels
• HP Powertrust power supplies (Uninterruptable Power Supplies)
With Serviceguard, you configure packages (collections of HP-UX and application
processes) on the nodes of your cluster. There are three types of Serviceguard packages:
Failover The most common type of Serviceguard package is the
Failover Package. A Failover Package is installed on
multiple nodes in a Serviceguard cluster, but runs only on
one node at a time. The node running the primary copy of
a Failover package is called the primary node. Should the
primary node fail, a copy of the package on another node
(known as an adoptive node) takes over with little or no
interruption in service until the primary node can be
restored to service. Multiple adoptive nodes can be defined
for extra redundancy.
Multi-node Multi-node Packages run (simultaneously) on one or more
nodes in a Serviceguard cluster. A multi-node package can
be configured to remain running as long as at least one copy
of the package remains running. Multi-node packages do
not fail over. HP supports them only for specific
applications.
System Multi-node System Multi-node Packages run (simultaneously) on all
nodes in Serviceguard cluster. They remain running as long
Clustering (Multiple Servers, One Operating System) 35