Hi All,
I’m a bit late to the party, but yes, @ZVeguillaCotto is correct.
With that, the fully built HL15 from us would be able to support all 15 SATA drives, or 7 SAS drives and 8 SATA drives.
If you wish to use all SAS drives, you would need to add another SAS controller to the system and have the backplane connect to that instead.