Vellemannv, The Perc Controller configuration you have shown would be fine. You can mix SAS and SATA drives on the controller, it can handle both. You can have SAS arrays and SATA arrays present on the same controller. You can NOT have SAS and SATA drives present in the SAME array though.  The OS will see the different virtual drives as well. Let me know if this helps.
Hello, On which level is this possible? Can I mix SATA and SAS disk on the RAID controller (PERC H710), group or virtual disk level? Server PowerEdge R720. The configuration I want to become is: PERC controller: - 2 SAS HDD in RAID 1 (for the OS) - 2 SATA SSD in RAID 1 (for Log files) - 6 SAS HDD in RAID 10 (for Database) Should this be in separate RAID groups? Can I combine SATA and SAS in a RAID group, virtual disk or only on the controller niveau? Will all my drives will be visible in Windows, not depending if it's SATA or SAS? Thanks!      
Mix SAS HDD with SATA SSD in RAID