Hello Stefgrifon,   The rear backplane daisy chain off the front backplane. It uses the same controller as the front backplane.   Page 107-108 Owners manual : [URL]   Figure 71 shows the cabling for the optional 2.5" x2 rear backplane.   I don't see any support for using a separate controller to the rear backplane.
Hello,   I have a server Dell R720xd with Perc h710 mini raid controller. I need to install Proxmox in my server  and i want to use ZFS, so i don't want to use any hardware raid like Raid0. Does Server and raid allow me to do this? if not How can i flash my raid controller? Thank you Stefanos  
R720xd with Perc H710 Mini no-raid Proxmox