Windows 8 has a new feature, which they call Storage Spaces. I won’t pretend to say I understand it, but I came across a blog from Microsoft that explains its principles.
In a nutshell it organizes physical disks into storage pools, which can have drives added or removed, and it makes use of virtual disks, known as spaces, which provide some resistance to data loss by mirroring data across the physical disks.
The blog can be seen here: http://blogs.msdn.com/b/b8/archive/2012/01/05/virtualizing-storage-for-scale-resiliency-and-efficiency.aspx
The part that really escapes me is “thin provisioning”. I can see how you can set up a logical 10tb pool using only 4tb of physical drives, but I don’t see how it can be useful to do so, as you have to add drives as you reach the limits of the physical storage.