Managing HP Serviceguard for Linux, Sixth Edition, August 2006

Understanding Serviceguard Software Components
Serviceguard Architecture
Chapter 3 37
Quorum Server Daemon: qs
The quorum server daemon provides tie-breaking services when needed
during cluster re-formation. The quorum server runs on a system
external to the cluster, and it is started by the user, not by Serviceguard.
It is normally started out of /etc/inittab, which means that it
automatically re-spawns if it fails or is killed. Additionally, the quorum
server can be run in a package in another cluster.
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