Chapter 42 Ha Configuration; Introduction To Ha; Configuring Ha - 3Com 8800 Configuration Manual

3Com Switch 8800 Configuration Guide

Chapter 42 HA Configuration

42.1 Introduction to HA

HA (high availability) is to achieve a high availability of the system and to recover the
system as soon as possible in the event of Fabric failures so as to shorten the MTBF
(Mean Time Between Failure) of the system.
The functions of HA are mainly implemented by the application running on the Fabric
and slave board. The two boards are working in the master-slave mode: one board
works in master mode, the other work in slave mode. If the master-slave system
detects a fault in the Fabric, a hot master-slave switchover will be performed
automatically. The slave board will try to connect and control the system bus while the
original Fabric will try to disconnect from the bus. Thus, the master-slave switchover of
the active system is completed, and at the same time the original Fabric is reset to
recover as soon as possible and then function as the slave board. Even if the Fabric
fails, the slave board can also take its role to ensure the normal operation, and the
system can recover as soon as possible.
The Switch 8800 supports hot swap of Fabric and slave board. The hot swap of
Fabricss will cause master-slave switchover.
The Switch 8800 supports manual master-slave switchover. You can change the
current board state manually by executing command.
The configuration file of slave is copied from the Fabric at the same time. This can
ensure that the slave system continues to operate in the same configuration as that of
the original active system after the slave system has taken place of the active system.
The Switch 8800 supports automatic synchronization. The active system stores its
configuration file and backup the configuration file to the slave system simultaneously
when the master's configuration file is modified, ensuring the consistency of the
configurations of the active system and slave system.
Besides, the system can monitor the power supply and the working environment of the
system and give timely alarms to avoid the escalation of failures and ensure safe
operations of the system.

42.2 Configuring HA

The following sections describe the HA configuration tasks:
Restarting the Slave System Manually
Starting the Master-Slave Switchover Manually
Enabling/Disabling Automatic Synchronization
Synchronizing the Configuration File Manually
42-1
Chapter 42 HA Configuration