The Problem with Storage Spaces

As you may well have gathered from a number of my previous posts about Windows Server 2012 and Storage Pools, I was intending on using them for my home server rebuild, and I am indeed using them, however I have neglected to post anything showing the new server (although I will change that shortly).

I ran into a problem with Storage Pools today which I think quite frankly blows. I got myself a new Western Digital 3TB Red drive to try out. The plan is to replace all of my existing six 2TB Western Digital Green drives with these for a number of reasons including greater bang for buck on power consumption, increased IOPS, cooler running temperature and improved reliability.

Not wanting to keep a mixture of Green and Red drives for very long, I proceeded to remove one of the drives from the pool to replace with a Red drive. The Storage Pool refused to remove it as a Simple non-redundant Storage Space was being hosted on this drive.

Problem 1:  Storage Spaces cannot be converted between Simple, Mirror or Parity. Once they are created, they are created. My only option for this was to create a new temporary Space marked as Mirror and copy the data from the Simple so that I could delete it. Once deleted, I tried a second attempt to remove the drive and I got an error that I needed to add another drive to the pool as there was insufficient capacity.

I’m sorry, what?

Problem 2: I have six 2TB drives in an uber-pool. I am currently less than half of it, so removing the drive should be no problem. I tried this a few more times and each time I got the same error that I would need to add more capacity to the pool before I would be able to remove the drive, which I know to be cobblers.

In the end, I just pulled the disk from the server and let the Storage Pool have a cry about the missing disk. From here, I marked the disk for removal to allow Windows to think that the disk was failed and that it was never coming back. This worked although is time consuming as it forces all Mirror and Parity virtual disks to enter a repairing state, copying blocks to remaining disks in the pool to keep up the protection level.

This brings me softly onto another point which is more of a beef.

Beef 1: One of the tricks of Windows Server 2012 was deduplication. Anyone familiar with Windows Server 2012 will know that Storage Pools and deduplication do work together, but in Essentials, deduplication is absent, missing, not there. The feature is completely missing from any of the Server Manager interfaces and from PowerShell, the command Get-Command -Module Dedup* returns nothing.

Why is it missing from Essentials? Essentials is the release of Windows Server 2012 targeted at SMB/SME and pro-home customers, the customers most likely to be storing a lot of data on a tight budget, so why strip out the feature that they will probably be highly interested in, in Windows Server 2012.

I really hope that Microsoft get enough complaints from customers of Essentials to release a Feature Update to re-add the support for deduplication.

With this done,


Richard works as a Cloud Consultant for Fordway Solution where his primary focus is to help customers understand, adopt and develop with Microsoft Azure, Office 365 and System Center. Richard Green is an IT Pro with over 15 years' of experience in all things Microsoft including System Center and Office 365. He has previously worked as a System Center consultant and as an internal solutions architect across many verticals. Outside of work, he loves motorbikes and is part of the orange army, marshaling for NGRRC, British Superbikes and MotoGP. He is also an Assistant Cub Scout Leader.

2 thoughts on “The Problem with Storage Spaces

  1. Hi Richard, interesting findings. I was playing last weekend with storage spaces in a virtual environment. What I found difficult was the extending part, that won’t allow you to extend a volume when you add a single disk. Apparently this is related to the number of columns for the particular VD in place, but the documentation is not deep enough. Did you find deep level documentation during as part of your testing that you can share? Have you ran into the same issue? Regards,

    1. Ignacio,

      To be honest, I didn’t read any of the documentation for Storage Spaces. I had a go with it in a Server 2012 Essentials VM before I decided to migrate my setup to Essentials, then once I was happy I could achieve my goals, I set it up for real. In my VM though, I didn’t realise I would face the issues with removal of drives (cleanly at least).

      For extensions, not a problem. I just popped in the new drives, added them to the pool and it just worked.

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