Managing Serviceguard 11th Edition, Version A.11.16, Second Printing June 2004

Planning and Documenting an HA Cluster
Cluster Configuration Planning
Chapter 4148
Cluster Lock Disks and Planning for Expansion
You can add additional cluster nodes after the cluster is up and running,
but doing so without bringing down the cluster requires you to follow
some rules. Recall that a cluster with more than 4 nodes may not have a
lock disk. Thus, if you plan to add enough nodes to bring the total to
more than 4, you should use a quorum server.
Cluster Configuration Parameters
For the operation of the cluster manager, you need to define a set of
cluster parameters. These are stored in the binary cluster configuration
file, which is located on all nodes in the cluster. These parameters can be
entered by editing the cluster configuration template file created by
issuing the cmquerycl command, as described in the chapter “Building
an HA Cluster Configuration.” The parameter names given below are the
names that appear in the cluster ASCII configuration file.
The following parameters must be identified:
CLUSTER_NAME
The name of the cluster as it will appear in the output
of cmviewcl and other commands, and as it appears in
the cluster configuration file.
The cluster name must not contain any of the following
characters: space, slash (/), backslash (\), and asterisk
(*). All other characters are legal. The cluster name can
contain up to 39 characters.
QS_HOST The name or IP address of a host system outside the
current cluster that is providing quorum server
functionality. This parameter is only used when you
employ a quorum server for tie-breaking services in the
cluster.
QS_POLLING_INTERVAL
The time (in microseconds) between attempts to
contact the quorum server to make sure it is running.
Default is 300,000,000 microseconds (5 minutes).
QS_TIMEOUT_EXTENSION