Managing Serviceguard Fifteenth Edition, reprinted May 2008

Understanding Serviceguard Software Components
Serviceguard Architecture
Chapter 3 61
Syslog Log Daemon: cmlogd
cmlogd is used by cmcld to write messages to syslog. Any message
written to syslog by cmcld it written through cmlogd. This is to prevent
any delays in writing to syslog from impacting the timing of cmcld.
Cluster Logical Volume Manager Daemon: cmlvmd
This daemon is responsible for keeping track of all the volume group(s)
that have been made cluster aware. When a volume group is made
cluster aware, a cluster node can only activate it in exclusive mode. This
prevents the volume group from being activated in write mode by more
than one node at a time.
Cluster Object Manager Daemon: cmomd
This daemon is responsible for providing information about the cluster to
clients—external products or tools that depend on knowledge of the state
of cluster objects.
Clients send queries to the object manager and receive responses from it
(this communication is done indirectly, through a Serviceguard API). The
queries are decomposed into categories (of classes) which are serviced by
various providers. The providers gather data from various sources,
including, commonly, the cmclconfd daemons on all connected nodes,
returning data to a central assimilation point where it is filtered to meet
the needs of a particular query.
This daemon is started by inetd(1M). There are entries in the
/etc/inetd.conf file.
This daemon may not be running on your system; it is used only by
clients of the object manager.
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. You
must edit /etc/SnmpAgent.d/snmpd.conf to tell cmsnmpd where to send
this information.