Brocade FastIron SX Series Chassis Hardware Installation Guide - Manual (Page 110)

Management module redundancy overview
When you power on or reload a FSX 800 or FSX 1600 chassis with two management modules
installed, by default, the management module installed in the lower-numbered slot becomes the active
module and the management module in the higher-numbered slot becomes the standby module. (You
can change the default active slot using the set-active-mgmt command. For information about
performing this task, refer to “Changing the default active chassis slot” section.)
After the active and standby modules are determined, both modules boot from the source specified for
the active module. The active management module boots from the active management module’s flash
memory.
After the modules boot, the active module synchronizes the standby module’s flash code and system-
config file with its own.
During normal operation, the active module handles tasks such as obtaining network topology and
reachability information and determining the best paths to known destinations. The active module also
monitors the standby module.
The standby module functions in an active standby mode. Keeping the system-config and running-
config files on both modules synchronized allows the standby module to assume the role of active
module seamlessly if necessary.
During a switchover, the standby management module takes over the active role and re-initializes all
the interface modules in the system that are not CLI-disabled by the administrator. This may cause a
brief interruption of the traffic forwarding.
Management module switchover
The following events cause the standby management module to become the active module, which is
called a switchover :
• The active module becomes unavailable
• You perform a manual switchover
• You remove and replace the active management module
The following sections explain how the switchover occurs for each event
Unavailable active module
The following events cause an active module to become unavailable and a switchover to occur:
• An active module experiences a problem significant enough to cause a system reset of the
module.
• The active module loses power.
When a switchover occurs, the active module resets itself and sends an interrupt signal to the standby
module. The standby module then becomes the active module and the interface modules continue to
forward traffic.
The new active module begins to manage the system. When the original active module becomes
available again or is replaced, it assumes the role of standby module.
Manual switchover
In some situations, you may want to manually switch the role of active management module from the
currently active module to the standby module. For instance, when you want to remove the current
active management module for maintenance. For example, if the module in slot 10 is the active
Management module redundancy overview
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