Managing Serviceguard A.11.20, March 2013

################## cmcluster.conf ###############
# Highly Available Cluster file locations
# This file must not be edited
#################################################
SGCONF=/etc/cmcluster
SGSBIN=/usr/sbin
SGLBIN=/usr/lbin
SGLIB=/usr/lib
SGRUN=/var/adm/cmcluster
SGAUTOSTART=/etc/rc.config.d/cmcluster
SGFFLOC=/opt/cmcluster/cmff
CMSNMPD_LOG_FILE=/var/adm/SGsnmpsuba.log
NOTE: If these variables are not defined on your system, then source the file /etc/
cmcluster.conf in your login profile for user root. For example, you can add this line to
root’s .profile file:
. /etc/cmcluster.conf
Throughout this book, system filenames are usually given with one of these location prefixes. Thus,
references to $SGCONF/filename can be resolved by supplying the definition of the prefix that
is found in this file. For example, if SGCONF is defined as /etc/cmcluster/, then the complete
pathname for file $SGCONF/cmclconfig is /etc/cmcluster/cmclconfig.
NOTE: Do not edit the /etc/cmcluster.conf configuration file.
Creating Cluster-wide Device Special Files (cDSFs)
Cluster-wide device special files (cDSFs) are persistent device special files applied across a set of
nodes. That is, they ensure that the same piece of storage has the same devicefile name on all of
the nodes that share it; no matter how many paths there are to the device, the same cluster DSF is
used to address it. If the device is moved, the same cDSF still addresses it.
For an overview, see “About Cluster-wide Device Special Files (cDSFs)” (page 109). For more
information about persistent device special files, see “About Device File Names (Device Special
Files)” (page 81).
Before You Start
Before you start, make sure you have read and understood the restrictions and limitations spelled
out under “About Cluster-wide Device Special Files (cDSFs)” (page 109). You should also read the
cmsetdsfgroup (1m) manpage.
If the cluster does not yet exist, make sure Serviceguard is installed on each prospective node.
Creating cDSFs for a Group of Nodes
Proceed as follows.
1. Identify the nodes for which you want to create cluster-wide device files; this is known as the
cDSF group.
This should be all the nodes in the cluster (or prospective cluster).
IMPORTANT: Remember that:
• You cannot create a cDSF group that crosses cluster boundaries; that is, the group must
consist of the nodes of a single cluster.
• cDSFs use agile addressing; see “About Device File Names (Device Special Files)”
(page 81) for information about agile addressing.
164 Building an HA Cluster Configuration