3Com Switch 8807, Configuration Manual

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HA C
ONFIGURATION
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 master
and slave modules. The two modules are working in the master-slave mode: one
module works in master mode, the other work in slave mode. If the master-slave
system detects a fault in the master module, a hot master-slave switchover will be
performed automatically. The slave module will try to connect and control the
system bus while the original master module 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 master module is reset to recover as soon as possible and
then function as the slave module. Even if the master module fails, the slave
module can also take its role to ensure the normal operation, and the system can
recover as soon as possible.
Switch 8800 Family series support hot swap of master and slave modules. The hot
swap of master modules will cause master-slave switchover.
Switch 8800 Family series support manual master-slave switchover. You can
change the current module state manually by executing command.
The configuration file of slave is copied from master module 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. Switch 8800 Family series support 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.
c
CAUTION: The Switch 8800 Family active and standby modules must both be in
position and run the same version of program. Otherwise, the switch cannot
operate normally.
Configuring HA
The following sections describe the HA configuration tasks:
■
“Restarting the Slave System Manually”
■
“Starting the Master-Slave Switchover Manually”