Computer Hardware User Manual

© Copyright IBM Corp. 1999 51
Chapter 3. Cluster Hardware and Software Preparation
This chapter covers the steps that are required to prepare the RS/6000
hardware and AIX software for the installation of HACMP and the
configuration of the cluster. This includes configuring adapters for TCP/IP,
setting up shared volume groups, and mirroring and editing AIX configuration
files.
3.1 Cluster Node Setup
The following sections describe important details of cluster node setup.
3.1.1 Adapter Slot Placement
For information regarding proper adapter placement, see the following
documentation:
•
PCI Adapter Placement Reference Guide, SA38-0538
•
Adapters, Devices, and Cable Information for Micro Channel Bus
Systems
, SA38-0533
•
Adapters, Devices, and Cable Information for Multiple Bus Systems ,
SA38-0516
3.1.2 Rootvg Mirroring
Of all the components used to build a computer system, physical disk devices
are usually the most susceptible to failure. Because of this, disk mirroring is a
frequently used technique for increasing system availability.
File system mirroring and disk mirroring are easily configured using the AIX
Logical Volume Manager. However, conventional file system and disk
mirroring offer no protection against operating system failure or against a
failure of the disk from which the operating system normally boots.
Operating system failure does not always occur instantaneously, as
demonstrated by a system that gradually loses access to operating system
services. This happens as code and data that were previously being
accessed from memory gradually disappear in response to normal paging.
Normally, in an HACMP environment, it is not necessary to think about
mirroring the root volume group, because the node failure facilities of HACMP
can cover for the loss of any of the rootvg physical volumes. However, it is
possible that a customer with business-critical applications will justify