Arstechnica have an excellent post on a new Windows 8 featured call Storage Spaces, which is basically the successor to the original concept of Drive Extender in Windows Home Server, a concept that so many were fond of…
With Storage Spaces, physical disks are grouped together into pools, and pools are then carved up into spaces, which are formatted with a regular filesystem and are used day-to-day just like regular disks.
Storage in a pool is then distributed among one or more spaces. Each space can have its own redundancy policy, with three kinds of fault tolerance offered: 2-way mirroring, 3-way mirroring, and RAID 5-like parity. With the mirrored options, a space’s data is stored either twice or three times within a pool. With the parity option, the system will compute additional information and store this within the pool. If any disk in the pool fails, the data can be reconstructed using this additional information.
The systems strength lies in its flexibility, simply create a space, even one that exceeds the storage you currently have, then just add new disks to the pool and regardless of how large they are or how they are connected, the pool will manage the expansion and optional migration.
The most interest detail came to light in the recent consumer preview of Windows 8, that storage pools are in fact included in the client now.
I’m sure the whilst users of the original Windows Home Server are very pleased to see the idea live on, I am sure there will be no upgrade path, other than what was involved in moving to Windows Home Server 2011, copy your data off and rebuild your server from the ground up, which is a long and fairly painful process.