Chapter 9 High Availability for FortiOS 5.0 : Operating a cluster : Backing up and restoring the cluster configuration
  
Backing up and restoring the cluster configuration
You can backup the configuration of the primary unit by logging into the web‑based manager or CLI and following normal configuration backup procedures.
The following configuration settings are not synchronized to all cluster units:
HA override and priority
The interface configuration of the HA reserved management interface (config system interface)
The HA reserved management interface default route (ha-mgmt-interface-gateway)
The FortiGate unit host name.
To backup these configuration settings for each cluster unit you must log into each cluster unit and backup its configuration.
If you need to restore the configuration of the cluster including the configuration settings that are not synchronized you should first restore the configuration of the primary unit and then restore the configuration of each cluster unit. Alternatively you could log into each cluster unit and manually add the configuration settings that were not restored.