Managing HP Serviceguard for Linux Ninth Edition, April 2009

on Red Hat or /var/log/qs/sq.log on SUSE and cmomd logs to
/usr/local/cmom/log/cmomd.log on Red Hat or
/var/log/cmom/log/cmomd.log on SUSE.
NOTE: The file cmcluster.conf contains the mappings that resolve symbolic
references to $SGCONF, $SGROOT, $SGLBIN, etc, used in the pathnames in the
subsections that follow. See “Understanding the Location of Serviceguard Files”
(page 147) for details.
Configuration Daemon: cmclconfd
This daemon is used by the Serviceguard commands to gather information from all
the nodes within the cluster. It gathers configuration information such as information
on networks and volume groups. It also distributes the cluster binary configuration
file to all nodes in the cluster. This daemon is started by the internet daemon,
xinetd(1M).
Parameters are in the /etc/xinetd.d/hacl-cfg and
/etc/xinetd.d/hacl-cfgudp files. The path for this daemon is
$SGLBIN/cmclconfd.
Cluster Daemon: cmcld
This daemon determines cluster membership by sending heartbeat messages to cmcld
daemons on other nodes in the Serviceguard cluster. It runs at a real time priority and
is locked in memory. The cmcld daemon sets a safety timer in the kernel which is
used to detect kernel hangs. If this timer is not reset periodically by cmcld, the kernel
will cause a system reboot This could occur because cmcld could not communicate
with the majority of the cluster’s members, or because cmcld exited unexpectedly,
aborted, or was unable to run for a significant amount of time and was unable to update
the kernel timer, indicating a kernel hang. Before a system reset resulting from the
expiration of the safety timer, messages will be written to syslog, and the kernel’s
message buffer, if possible, and a system dump is performed.
The duration of the safety timer depends on the cluster configuration parameter
MEMBER_TIMEOUT, and also on the characteristics of the cluster configuration, such
as whether it uses a quorum server or a cluster lock (and what type of lock) and whether
or not standby LANs are configured.
For further discussion, see “What Happens when a Node Times Out” (page 88). For
advice on setting MEMBER_TIMEOUT, see Cluster Configuration Parameters (page 100).
For troubleshooting, see “Cluster Re-formations Caused by MEMBER_TIMEOUT Being
Set too Low” (page 282).
cmcld also manages Serviceguard packages, determining where to run them and
when to start them. The path for this daemon is: $SGLBIN/cmcld.
Serviceguard Architecture 39