Managing Serviceguard 14th Edition, June 2007

Building an HA Cluster Configuration
Preparing Your Systems
Chapter 5 219
For a complete discussion of how the quorum server operates, see to
“Cluster Quorum to Prevent Split-Brain Syndrome” on page 65. See the
section “Specifying a Quorum Server” on page 237 for a description of
how to use the cmquerycl command to specify a quorum server in the
cluster configuration file.
For more information, see the Release Notes for your version of Quorum
Server at http://docs.hp.com -> High Availability -> Quorum
Server.
Ensuring Consistency of Kernel Configuration
Make sure that the kernel configurations of all cluster nodes are
consistent with the expected behavior of the cluster during failover. In
particular, if you change any kernel parameters on one cluster node, they
may also need to be changed on other cluster nodes that can run the
same packages.
Enabling the Network Time Protocol
It is strongly recommended that you enable network time protocol (NTP)
services on each node in the cluster. The use of NTP, which runs as a
daemon process on each system, ensures that the system time on all
nodes is consistent, resulting in consistent timestamps in log files and
consistent behavior of message services. This ensures that applications
running in the cluster are correctly synchronized. The NTP services
daemon, xntpd, should be running on all nodes before you begin cluster
configuration. The NTP configuration file is /etc/ntp.conf.
For information about configuring NTP services, refer to the HP-UX
manual HP-UX Internet Services Administrator’s Guide posted at
http://docs.hp.com -> Networking and Communication -> Internet
Services.
Tuning Network and Kernel Parameters
Serviceguard and its extension products such as SGeSAP, SGeRAC, and
SGeFF, have been tested with default values of the supported network
and kernel parameters in the ndd and kmtune utilities.
Adjust these parameters with care.