 
                 
                                     
                             
				The number of supported ES24F Expansion shelves that can be attached depends on the TrueNAS system it will be attached to. Top of the line M60 appliance can attach up to 12x expansion shelves, while the TrueNAS H10 can only support a single expansion shelf. SAS expanders in the controllers on a TrueNAS system connect to the expansion shelf controller. TrueNAS systems with just a single controller do not offer high-availability (HA) but can be modified with the addition of another controller for HA.
 
		Wide porting by connecting a TrueNAS systems 2x SAS ports to the 2x SAS connection to a single Expansion Shelf will double the bandwidth between the TrueNAS system and connected Expansion Shelf. If another Expansion Shelf is added later, then one of the connections from the TrueNAS system can be routed to the other Expansion Shelf.