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

Appendix A 947

A Using High Availability

Strategies

High availability is the term used to describe computer systems that

have been conﬁgured so as to minimize the percentage of time that they

will be down or otherwise unavailable, and as a result, allow for the

greatest degree of usefulness. High system availability is achieved by

minimizing the possibility that a hardware failure or a software defect

will result in a loss of the use of the system or in a loss of its data.

Improved system and data availability can therefore result from

advantageous use of either hardware and/or software components which

serve to reduce the impact of errors by making use of redundant and

isolated components such as dual busses, I/O devices, and duplicate

copies of data.

Some of the various means of implementing high availability that should

be considered in administering HP-UX systems are reviewed here.

NOTE High availability is a complex topic that can only be brieﬂy summarized

here. For a more complete technical discussion, please refer to the white

paper, Choosing the Right Disk Technology in a High Availability

Environment. This document can be found on the HP documentation web

site, http://docs.hp.com. Select “High Availability” and then “White

Papers.”

HP References • Chapter 6, “Administering a System: Managing Disks and Files,” on

page 555, particularly:

❏ “Managing Disks” on page 556

❏ “Managing Mirrored File Systems” on page 627

• Conﬁguring OPS Clusters with ServiceGuard OPS Edition

• Managing Serviceguard

• Designing Disaster Tolerant High Availability Clusters

• HP-UX ServiceControl User’s Guide

• Using Advanced Tape Services

• Using High Availability Monitors

• Clusters for High Availability: A Primer of HP Solutions, HP Press,

published by Prentice Hall PTR, 1996

• Disk and File Management Tasks on HP-UX, HP Press, published by

Prentice Hall PTR, 1997