Afreire, You can use enterprise class SATA drives up to 4TB  in the remaining slots. You will need carriers for the drives, even if they are non-RAID.   The H310 controller supports the use of JBOD (just a bunch of drives)  without having them in a RAID.   OpenManage will see them as non-RAID drives.  Regards,  
Hello experts,  I have a T420 server with 8 bay running 2 SATA 3"5 Hot swap Dell Hard Drives.  The controller is a Perc H310.  I would like to know what kind of hard drives could fit into empty bays. I would like to use non-Hot Swap drives as well to extend storage. Can I buy standard 3"5 7200 RPM Sata Hard Drivies? Will it work? Thanks in advance. Appreciate your attention. Regards 
Hard Drives compatible with Dell T420 Perc H310