Standby AMM

Because an AMM failure results in a configuration loss, it is best practice to install a standby AMM when using BOFM.

The BOFM configuration is not included in the AMM configuration backup. Such a backup would allow BOFM configuration updates from a file that might be outdated. This would cause inconsistencies with the configuration of other chassis.
The BOFM configuration is chassis-based and does not transfer with the physical AMM. When an AMM is moved to a new chassis, it clears out its BOFM configuration, and the BOFM configuration must be reapplied on the new AMM.
Note: When an AMM is moved to a new chassis, it clears the configuration for all slots except for slots that have blades powered-on with a valid BOFM configuration that is already in use. For these slots, the AMM uses the BOFM configuration as defined on the blades.

If the AMM configuration is reset to factory defaults, the BOFM configuration is handled as if a new AMM was installed in the chassis.

If the primary AMM fails, the standby AMM contains the BOFM configuration and takes over. As an additional precaution, you should always save your BOFM configuration file or files via the BOFM interface whenever changes are made or a new configuration is applied.

If you only have one AMM installed in the chassis and you must replace it, before you replace it, insert the new AMM as a standby unit, let it power on and wait for a few minutes. This allows the BOFM configuration to be transferred to the new unit. You can remove the old unit and you do not have to reapply the BOFM configuration.
Note: You might have to wait longer than a few minutes, if the AMM you insert in the standby slot does not have the same firmware level as the primary.