Managing Serviceguard Fifteenth Edition, reprinted May 2008

Troubleshooting Your Cluster
Solving Problems
Chapter 8 429
nslookup ftsys9
Name Server: server1.cup.hp.com
Address: 15.13.168.63
Name: ftsys9.cup.hp.com
Address: 15.13.172.229
If the output of this command does not include the correct IP address of
the node, then check your name resolution services further.
In many cases, a symptom such as Permission denied... or
Connection refused... is the result of an error in the networking or
security configuration. Most such problems can be resolved by
correctingthe entries in /etc/hosts. See “Configuring Name Resolution”
on page 203 for more information.
Cluster Re-formations
Cluster re-formations may occur from time to time due to current cluster
conditions. Some of the causes are as follows:
• local switch on an Ethernet LAN if the switch takes longer than the
cluster NODE_TIMEOUT value. To prevent this problem, you can
increase the cluster NODE_TIMEOUT value, or you can use a different
LAN type.
• excessive network traffic on heartbeat LANs. To prevent this, you
can use dedicated heartbeat LANs, or LANs with less traffic on
them.
• an overloaded system, with too much total I/O and network traffic.
• an improperly configured network, for example, one with a very large
routing table.
In these cases, applications continue running, though they might
experience a small performance impact during cluster re-formation.