What the fdisk? Storage Spaces Direct just vanished from Windows Server in version 1709
Found on The Register on Wednesday, 18 October 2017
Support for Storage Spaces Direct, Microsoft's version of VSAN, has been stripped from the latest build of Windows Server 2016, version 1709, which was released on Tuesday.
Storage Spaces Direct, as the name suggests, handles direct-attached SAS, SATA or SSD drives.
So much for relying on Microsoft for not removing components you had before.