@tim_g said in Port - Storage Spaces Direct (S2D): SCSI Enclosure Services (SES) needed only on HBA?: @dashrender RAID would be provided by SS. He would need a controller that is pass-through. Technically S2D is designed to be used by DAS systems (or JBODs if you like to make Scott facepalm), and not internal server storage... even though it works just fine. There's no problem to use RAID controller instead of a basic HBA as long as you a) patch the registry (see my link below) or use special "filter" driver to report "RAID" bus (sic!) as SATA or SAS, and b) disable write-back cache on BOTH controller and disk itself, so all writes become atomic. Storage Spaces Direct: Enabling S2D work with unsupported device types (BusType = NVMe, RAID, Fibre Channel). Part 1: Registry hack https://www.starwindsoftware.com/blog/resolving-enable-clusters2d-bus-type-support-issue-on-some-storage-controllers P.S. It's a BAD idea to use anything like that in production because as long as Microsoft support will discover your S2D configuration isn't supported they will pull out and walk away with a grin face.