Managing HP Serviceguard for Linux, Seventh Edition, July 2007

Understanding Serviceguard Software Components
Serviceguard Architecture
Chapter 338
All members of the cluster initiate and maintain a connection to the
quorum server. If the quorum server dies, the Serviceguard nodes will
detect this and then periodically try to reconnect to the quorum server
until it comes back up. If there is a cluster reconfiguration while the
quorum server is down and there is a partition in the cluster that
requires tie-breaking, the reconfiguration will fail. The path for this
daemon is:
• For SUSE: /opt/qs/bin/qs
• For Red Hat: /usr/local/qs/bin/qs
Utility Daemon: cmlockd
Runs on every node on which cmcld is running. It maintains the active
and pending cluster resource locks.
Cluster SNMP Agent Daemon: cmsnmpd
This daemon collaborates with the SNMP Master Agent to provide
instrumentation for the cluster Management Information Base (MIB).
The SNMP Master Agent and the cmsnmpd provide notification (traps)
for cluster-related events. For example, a trap is sent when the cluster
configuration changes, or when a Serviceguard package has failed. To
configure the agent to send traps to one or more specific destinations,
add the trap destinations to /etc/snmp/snmptrapd.conf (SUSE and
Red Hat). Make sure traps are turned on with trap2sink in
/etc/snmp/snmpd.conf (SUSE and Red Hat).
The installation of the cmsnmpd rpm configures snmpd and cmsnmpd to
start up automatically. Their startup scripts are in /etc/init.d/. The
scripts can be run manually to start and stop the daemons.
For more information, see the cmsnmpd (1) manpage.