What’s New in v4.0 MR3 : High Availability improvements
 
High Availability improvements
FortiManager v4.0 MR3 brings improvements to HA mode:
Automatic firmware updating to slave units when the primary unit is upgraded
Automatic removal of inoperable slave units, with notification to the administrator indicating that action is required
Improved uptime and availability enhancements.
Please review the High Availability section of this document, located on page 355 for further information.