Storage Spaces is a new feature with Windows 8. How it works is similar to Windows Server 2012 where a block of disks are grouped and a software RAID is then used to prevent data loss.
Storage Spaces is a storage virtualization technology which succeeds Logical Disk Manager and allows the organization of physical disks into logical volumes similar to Logical Volume Manager (Linux), RAID1 or RAID5, but at a higher abstraction level.
With Windows on a SSD, a Storage Spaces block of 3 or more disks offer n-1 capacity with tolerance for one disk failing. With a block of 7 or more disks Storage Spaces offer n-2 fault tolerance.
Storage spaces can use USB, SATA or SAS disks. SATA cards are low cost and larger scale NAS units can also leverage Storage Spaces.
An ATX chassis can hold 4 disks and if the system volume is a SSD, then 3 hard disks can make up a Storage Spaces setup. The HAF 932 has 5 disk bays.