Managing Serviceguard Fifteenth Edition, reprinted May 2008

Building an HA Cluster Configuration
Preparing Your Systems
Chapter 5 207
This step is critical, allowing the cluster nodes to resolve hostnames to IP
addresses while DNS, NIS, or the primary LAN is down.
Step 4. Create a $SGCONF/cmclnodelist file on all nodes that you intend to
configure into the cluster, and allow access by all cluster nodes. See
“Allowing Root Access to an Unconfigured Node” on page 200.
NOTE HP recommends that you also make the name service itself highly
available, either by using multiple name servers or by configuring the
name service into a Serviceguard package.
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
HP strongly recommends 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.