The Spirit of Drive Extender is Alive and Well – It’s Called Storage Spaces in Windows 8

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.



  1. I wonder wether this will mean an early end for support for WHS 2011 if most features are present in Win 8. They just have to add the possibility to backup other computers to Win 8 and WHS 2011 will be obsolete.

    1. we can already back up to network shares with the os internal backup functionality (but not as nice and pretty and awesome as whs’ solution, of course).

      or one can use something like crashplan, which allows network internal backups for free + allows the option to store stuff in their cloud. i use that for my external friends to back up to my whs (that’s for free, too)

  2. My *guess* is that may be where we’re headed, but we’ll see…. I’ll be looking closely at Win 8’s Backup and Remote Access to see if it’ll make a recent replacement. My hunch is that it will, and better that than the features we rely on being dropped by Microsoft if WHS 2011 isn’t replaced.

    1. Baring my great excitement and playing Devil’s advocate. What does this mean exactly? I wonder if they will deploy Windows 8, home, Premium, Ultimate, HMServer and what the price will be. Will the price for a server client make the software $500? It may be rare of me but I actually liked that WHS was its own specialized distribution that locked out many of ports and options that can plague Windows with Viruses. I am a Windows head and can’t wait to see Windows 8 in action but if it is all to generalized I will begin to wonder if my next server install won’t be Amahi.  I have always loved that the server was just a server and absolutely thought that the simple user interface, setup and easy deployment of WHS made it the best choice for me. My customers love it as it just sits there and works every day. Please Microsoft just makes a WHS8 or something and prices it as you did V1!

  3. Looks like maybe I’ll finally be able to update my WHSv1 to a more modern OS, as long as there’s a version of this that works headless and has WHS’ excellent backup features.

  4. So, I guess that just about the time people start getting comfortable with their new choices for implementing drive pooling, MS is going to roll out yet another product to muddy the home server waters.  Having tested the Windows 8 Developer’s Preview, and tenaciously stuck with it through the initial shock of the new interface, I’s have to say I won’t go anywhere near Windows 8 as a keyboard/mouse based system.  This OS is all about touch based systems and I seriously doubt it will grab any traction in the home server market, drive pooling or no.

    1. @151868941c8b0a864c8e74adc0e4bf72:disqus I agree with you.

      What I think MSFT is doing here is a gamble. If Metro is a success for desktops they will claim ‘I told you so” (which is highly unlikely as you’re not the only one to think Metro has no space on the desktop/workstation model).

      If MSFT come to its senses then they will say “but we always thought of Metro as being a shell that goes in parallel with the traditional Windows desktop!”

      In sum I think MSFT is just pushing Metro as much as they can so people can get used to it and it increase its acceptance at all fronts, even if it doesn’t become a desktop shell.

      I urge you all to watch a movie call Idiocracy (2006). It has a scene in a hospital with an idiot using a touch computer that reminds me of Metro.

  5. Yay! The only issue I see if for those people who got WHS 2011, and doesn’t have this functionality 🙁 (I stuck with WHS 1).

    Since this is an NTFS feature I don’t think this will be ported back to WHS 2011. Perhaps a new version of WHS or, worst case scenario, just Windows 8 server.

  6. Hmmm. With the DE replacements like DB out, I was just waiting a few months to ensure there were no major bugs in them before upgrading to 2011. Now, I’m wondering if I should just wait for WHS 2013 and see if this if brought back in. I’d rather trust my data with an MS solution then some 3rd party.

    Decisions, decisions….

  7. Someone want to help me understand how this translates to an actual implementation, with no eSata being mentioned?  Do I now have to have all disks connected externally, through some sort of external USB 3.0 hub or something?  Just trying to figure out the physical layout of a “server” in this architecture.

    1. Regular (internal) SATA drives are supported, just not external SATA drives. Drives on sleds and other hot swap trays typically use standard SATA conections or SAS, so I don’t see any issues.

      1. eSATA is just a special case of SATA. Much of the time the OS doesn’t even know the difference unless the device is specifically marked for hotswaping. If it supports SATA, I’m sure it supports eSATA. For that matter I’m sure Firewire is supported too, though it’s probably not worth mentioning since so few people use it these days.

  8. I wonder if there’s any chance of seeing Storage Spaces added to WHS2011. Probably not. But will Client 8 or Server 8 have the backup features that we have in WHS2011?

    1. That is the Big Question (for me at least) at this point.  I can’t wait to get my hands on Windows 8, but I feel there is a lack of information in regard to how Win 8 with Storage Pools compares to WHS 2011 (or even v1 for that matter).  Storage Pools sound awesome, but I can get by fine without them (as evidenced by my WHS 2011).  Client backup, on the other hand, is something I WILL NOT give up just to get storage pooling back.  I use the backup and restore feature too often to let it go quietly. 🙂

  9. I am glad they appear to be taking the need for a drive pool technology seriously. It absolutely should have been integrated from the beginning on a low OS level. The shoestring nature of WHS v1 was sort of a blessing AND a curse here.

    I’m not so sure about Windows 8 client working well as an always-on home server. Maybe once you strip out all the non-essential services and presentation layers like Metro. Part of me really wants a server OS – simple, efficient and very robust. I can live with crashes on my desktop machine, but rely on my server to basically never crash (and in three years it has crashed only twice – each time due to my own stupidity).

    1. i never had any of my desktops crashing outside of when i’m stupid. same for the server. windows is 100% stable except if you have strange hw that fails/drivers that fail.

      in essense, except for the special whs services, my home server is just another win7 client (win2008r2 is just win7 with a bit different default settings). so i have no issue in using win8 as a server for my next whs (or win2012 server, or whs3, or what ever will be most fitting).

      and putting up a small touchscreen to the server + win8 ui will be great. why? because it’ll allow me to rip movies on the server directly non-automatically (means specifying name and all as needed). and it would be a nice watch, and stuff.. 🙂

      win8 metro will be a perfect home server console interface. and the os will be just as stable as any other: rock solid on the right hw.

  10. This is definitely an exciting step by MS. I just wish they’d introduce checksumming to tackle bit-rot as well.

    I do hope they still keep WHS as a separate SKU, for the security benefits others have mentioned,  but it would be also be cool if the WHS team configured the next version of WHS to use server core, not including a desktop UI at all. Which would cut resource usage of the OS to a minimum.

    They could expose all the WHS features like backup through powershell, and build the home server console on top of the new Windows 8 server manager. It would be great to have the opportunity to install the metro UI on the server itself, but it would make sense to be shipped with server core as the default.

    There is a bit more info on server core here, if anyone is interested:  

    1. The desktop UI has its place, no different to all other versions of windows server. Unfortunatly not everything you might want to run on a WHS actually supports WHS. However a hybrid of enabled/disabled UI etc.. would not be a bad move.

  11. storage spaces has never been a suitable replacement for drive extender. drive extender’s main selling point was that if a drive died only the data on that drive was affected. i could still read the other drives fine and i could even take a drive out to any computer that can use ntfs. i could have several hdd lose all but one of them instantly and still read the data on that one. storage spaces makes it possible to lose all your data when a subset of your drive fails

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