The size of 960GB SATA sounds like a 960GB ReadIntensive SATA SSD. The question is what RAID HBA you ordered with the Server. Because you ordered also "unconfigured raid" you must need to pre-configure a Diskgroup/Virtual disk within iDRAC or System setup before it comes visible in the OS. The BOSS-S2 is a special BootOptimizedStorageSolution for placing the OS on a simple raid or non raid(up to 2x M.2 SSDs). As every HBA its visible in the System-Setup->Devices->BOSS. Iam pretty sure you can reconfigure it, but in my opinion it doesnt make any sense. Keep in mind that multiple vDisk are not support on BOSS-S2. Iam not sure if you get any advantages if you disable the mirroring. If you dont have a need for it i suggest not to buy one next time because for the same money you will get another 960GB SSD or a 480 for RAID0 and you will save some money. Regards,Joerg
This is a new R750 with Windows Server 2019, with three SATA 960GB drives.  In the BIOS, all the ports are grayed out and SATA is enabled in AHCI Mode.  I only see one drive in the Windows Server partition information (two partitions are created on one drive).  I suspect none of the three SATA drives are available, and it's not clear why.  I am missing something; how can I make these three drives available, and viewable in Windows Server?
Dell R750 SATA Drives Aren't Available