Microsoft today provided another lengthy explanation of a new Windows 8 feature. Called Storage Spaces, this feature appears to be the logical (but not technical) successor to Windows Home Server's ill-fated Drive Extender technology, providing Windows with a way to virtualize storage across multiple devices into a single, easily accessible pool.
According to Microsoft, Storage Spaces provides two basic features, but I've added a third that I think is right up there (the middle one):
Storage pools. Physical disks are organized into storage pools, which can be easily expanded by simply adding disks. These disks can be connected either through USB, SATA (Serial ATA), or SAS (Serial Attached SCSI). A storage pool can be composed of heterogeneous physical disks – different sized physical disks accessible via different storage interconnects.
Mirroring. This optional feature of storage pools ensures that we at least two (and optionally three) complete copies of data are stored on different physical disks within the pool.
Virtual disks. Virtual disks (also known as spaces) behave just like physical disks for all purposes. However, spaces also have powerful new capabilities associated with them such as thin provisioning (storage space is reserved only when you need to use it), as well as resiliency to failures of underlying physical media.
Yep. Sounds like Drive Extender to me.
Of course, Storage Spaces is implemented completely differently from Drive Extender and is, in fact, a feature of the latest version of NTFS. As with DE, you can't boot from a Storage Space pool, but only from a "normal" hard disk/storage device, and there are bits in there for adding and removing physical storage from a pool.
Good stuff, and long overdue. Read the post for all the details.