Overview - HP 9000 Installation And Configuration Manual

ACC Service Guard Configuration Notes

Overview

84
Overview
In the examples, there are two systems that each have one or more ACC
cards, using the dual connect ACC distribution panel accessories. One
system is a primary, and one is a secondary. The primary system has the
ACC links in active use, and the secondary either does not start the ACC
subsystem, or has each link (pmode) in the loopback mode.
There are 2 cases that need to be considered.
• In the first case, the primary system has an unexpected, catastrophic
failure or HP-UX panic.
• In the second case, the primary system is shutdown (gracefully).
The SG cluster configuration is controlled by a script, run on each system
when the system joins the cluster. The script is invoked with options that
indicate which subsystems are to be made active, and which are to be
inactive.
To control the behavior, in both cases you need to do the following:
1. In the network configuration file, /opt/acc/cfg/loopback.answ (or
the filename you choose), define the port mode for each link to be
LBACK. You also need to define Term's for monitor (one for each
ACC card).
2. In the control file, /opt/acc/cfg/zmasterd_list, add statements to
start watch and stop watch. The watch daemon is the heart beat
generation for the ACC monitor protocol.
When started, watch enables monitor, and then sends a heartbeat to
monitor. Monitor will reset the ACC, if a heatbeat is missed. The
ACC reset will put the ACC ports in LBACK (tri-state).
This handles the case of an unexpected failure where the Service
Guard cluster control script does not run with the stop option.
You also need to make the file path for zmon correct
(/opt/acc/cfg/loopback.tmem).
Appendix C