For deployment that uses more than one MX chassis, the chassis must be in a multichassis management (MCM) group. See the Dell OpenManage Enterprise-Modular Edition for PowerEdge MX7000 Chassis User's Guide on the Documentation page of the support site for information about how to create the MCM group.
Note: SmartFabric mode can be enabled on a single chassis that has two MX9116n Fabric Switch Engine (FSE) switches or two MX5108n ethernet switches. For a SmartFabric implementation that uses a single chassis, creating an MCM group is not mandatory but is recommended. The chassis must be in an MCM group for a SmartFabric that uses more than one MX chassis.