Early in December, it dawned on me that Microsoft may well be seeking to integrate some of the features we know and love(d) in Windows Home Server into Windows 8, particularly in the area of storage management. Today, on the company's Building Windows 8 blog, Microsoft confirmed that the spirit, if not the architecture of Drive Extender would be delivered in the company's forthcoming client refresh.

From Steven Sinofsky's introduction:

Many of us have been using Windows Home Server Drive Extender and have been hoping for an approach architected more closely as part of NTFS and integrated with Windows more directly. In building the Windows 8 storage improvements, we set out to do just that and developed Storage Spaces.

I won't rehash Rajeev Nagar's detailed explanation of Storage Spaces here, but note the following:

• In Windows 8, you will be able to create a unified storage pool comprising disks of various sizes, connected through a variety of interfaces (USB, SATA (Serial ATA), or SAS (Serial Attached SCSI) – interestingly eSATA and Firewire are not mentioned in this list).
• Data stored in the pool can be automatically protected through mirroring across two or more disks. Should a pool disk fail, Storage Spaces will invisibly self-heal by reallocating at risk data to other, healthier disks in the pool.
• Storage spaces extends the features of Drive Extender with thin provisioning, a previously Enterprise-oriented feature which allows creation of a pool that is larger than the physical storage available within the pool. Storage can be claimed or released by the pool as required (i.e. when you copy files to the pool, or delete files from the pool).
• Multiple spaces (pools) can be defined by the user, and therefore released space can be made available dynamically for other pools as required. Storage Spaces manages the allocation of space from your various disks automatically.
• Two types of data protection are available – the standard mirroring (duplication) technique, alongside a parity attribute which adds redundancy information to your data, allowing it to be reconstructed in case of disaster. According to the post, parity-based resilience is better suited to videos and photos (larger files, updated less often) vs mirroring-based resilience which is better suited to small files which are updated more often (e.g. documents).
• Storage Spaces can be created via the standard Windows (Control Panel) interface, as well as PowerShell for the geeks.
• Drive Letters are in. Storage Spaces are allocated drive letters and once created, can be managed like any other “disk” (including BitLocker support)

Nagar adds (My emphasis):

…some of us have used (or are still using), the Windows Home Server Drive Extender technology which was deprecated. Storage Spaces is not intended to be a feature-by-feature replacement for that specialized solution, but it does deliver on many of its core requirements.  It is also a fundamental enhancement to the Windows storage platform, which starts with NTFS. Storage Spaces delivers on diverse requirements that can span deployments ranging from a single PC in the home, up to a very large-scale enterprise datacenter.

Whilst limited elements of Storage Spaces have been delivered in the existing Windows 8 Developer Preview, expect to see a more comprehensive solution in the forthcoming Windows 8 Beta release (rumoured for February).

In today's blog post, Microsoft are dropping heavy hints that they consider Windows 8 Client to be the natural successor to Windows Home Server – via nods from both Steven Sinofsky and Nagar as to the Storage Spaces' provenance as well as a FAQ regarding migration from WHS v1 to Windows 8.

Q) I use Windows Home Server with Drive Extender. Is there a tool to help me migrate data from the Drive Extender format to Storage Spaces?

No. You will need to create a pool on a Windows 8 PC with a fresh set of disks. Then, you can simply copy data over from your Drive Extender-based volumes to a space within your pool. The functionality delivered through Storage Spaces is more flexible and better integrated with NTFS, so it will generally be more reliable and useful.

Having read today's post, Windows 8 certainly got a lot more interesting for me personally. I'm ambivalent as to whether the features we've come to know and love in WHS should exist in a standalone SKU or in Windows Client. If anything, whilst the WHS feature set may well be subsumed into the monolithic client SKU, if Windows 8 can deliver leading-edge storage management and data protection, a strong media serving solution, easy remote access and comprehensive user management, I couldn't care less how the product is branded. If Windows 8 results in the loss of Windows Home Server to the world, if the feature set is delivered, nurtured and developed, then Long Live the King.

At this point, Storage Spaces looks a little more complex than Drive Extender, and Microsoft's marketing teams should now get into some work simplifying the more technical terminology and user experience that currently exists in the feature (Mirroring? Parity? Resilience? Thin Provisioning? etc.) but it's a big step forward for the Windows client platform, and a world away from the disappointment of Windows Home Server 2011′s storage management.

There's still a lot to learn about Windows 8, but at the very least – based on today's post – it appears that Microsoft did indeed take note of the thousands of negative comments you (and I) made about the loss of Drive Extender in Windows Home Server 2011, and have worked not only to make amends, but to bring that same spirit of seamless storage management and data protection to an audience of millions.