Managing Serviceguard Nineteenth Edition, Reprinted June 2011

For services, cmcld monitors the service process and, depending on the number of service retries,
cmcld either restarts the service through cmserviced or it causes the package to halt and moves
the package to an available alternate node.
Quorum Server Daemon: qs
Using a Quorum Server is one way to break a tie and establish a quorum when the cluster is
re-forming; the other way is to use a cluster lock. See “Cluster Quorum to Prevent Split-Brain
Syndrome” and “Cluster Lock ” (page 44).
The Quorum Server, if used, runs on a system external to the cluster and is started by the system
administrator, not by Serviceguard. It is normally started from /etc/inittab with the respawn
option, which means that it automatically restarts if it fails or is killed. All members of the cluster
initiate and maintain a connection to the Quorum Server; if it dies, the Serviceguard nodes will
detect this and then periodically try to reconnect to it. If there is a cluster re-formation while the
Quorum Server is down and tie-breaking is needed, the re-formation will fail and all the nodes will
halt (system reset). For this reason it is important to bring the Quorum Server back up as soon as
possible.
For more information about the Quorum Server software and how it works, see the latest version
of the HP Serviceguard Quorum Server release notes at http://www.hp.com/go/
hpux-serviceguard-docs under HP Serviceguard Quorum Server Software
Network Manager Daemon: cmnetd
This daemon monitors the health of cluster networks, and performs local LAN failover. It also
handles the addition and deletion of relocatable package IP addresses for both IPv4 and IPv6.
Lock LUN Daemon: cmdisklockd
If a lock LUN is being used, cmdisklockd runs on each node in the cluster and is started by
cmcld when the node joins the cluster.
Utility Daemon: cmlockd
Runs on every node on which cmcld is running (though currently not actually used by Serviceguard
on HP-UX systems).
Cluster WBEM Agent Daemon: cmwbemd
This daemon collaborates with the Serviceguard WBEM provider plug-in module (SGProviders)
and WBEM services cimserver to provide notification (WBEM Indications) of Serviceguard
cluster events to Serviceguard WBEM Indication subscribers that have registered a subscription
with the cimserver. For example, an Indication is sent when the cluster configuration changes,
or when a Serviceguard package has failed.
You must edit /etc/rc.config.d/cmwbemagt to auto-start cmwbemd. Configure cmwbemd to
start before the Serviceguard cluster comes up. You can start and stop cmwbemd with the commands
/sbin/init.d/cmwbemagt start and /sbin/init.d/cmwbemagt stop.
Proxy Daemon: cmproxyd
This daemon is used to proxy or cache Serviceguard configuration data for use by certain
Serviceguard commands running on the local node. This allows these commands to get the data
quicker and removes the burden of responding to certain requests from cmcld.
CFS Components
The HP Serviceguard Storage Management Suite offers additional components for interfacing with
the Veritas Cluster File System on some current versions of HP-UX (see “About Veritas CFS and
CVM from Symantec” (page 22)). Documents for the management suite are posted on http://
www.hp.com/go/hpux-serviceguard-docs.
Serviceguard Architecture 41