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Do you have several physical hard-drives on your computer, but would like to have them collaborating as one? This can be useful for smaller SSD-drives or similar.

A quick Note before we continue!
Spanned volumes are not RAID volumes and they are not fault tolerant. If one of the disks in the volume should fail, you lose the data on both disks. That being said, let’s continue…


There are two ways to combine volumes into one: the Disk Management tool or the command line utility. Both methods require you to have Administrative privileges. You should also make a backup of whatever is on the disks before you continue, just to be on the safe side of things. I’ll show you the GUI way.

Disk Management tool

You need at least two dynamic disks in addition to the startup disk to create a spanned volume. All disks can be converted into a dynamic volume using the Disk Management tool. You can extend a spanned volume onto a maximum of 32 dynamic disks. If you haven’t converted your disks to Dynamic Volumes, you will have to erase a drive, making it unallocated – and thereby loosing all data on it.

There are many ways to get access to the Disk Management Tool and everyone has their own favorite. Mine is Right Clicking the Computer Icon and choose Manage. From there I activate the Disk Management Tool. I know there are faster ways, but …

Converting a Volume

To convert a volume from a Basic Volume to a Dynamic one you have to delete the volume first.

  • Right Click Volume to convert, Choose DELETE
  • Right Click the unallocated volume and choose CONVERT TO DYNAMIC

Repeat steps for all disks you want to convert.

Creating Spanned Volumes

  • Right Click one of the dynamic volumes and choose New Spanned Volume,
    the New Spanned Volume wizard starts
  • Follow the on-screen instructions. When asked add all disks to include in the spanned volume.
  • When the span wizard is done, you should be asked to assign a drive letter and format the drive (NTFS is the only choice available).

Now your large spanned volume should be ready to use.

If you would rather use the Diskpart Utility (Command Line Tool) then you can read more about that at Microsoft TechNet.

About Thomas

Computer geek from the age of 7, which amounts to 30 years of computer experience. From the early days (when every computer company had their own OS) of DOS, Windows 1.0 through Seven...

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6 thoughts on “Span Volumes, Make Windows Think Two Drives are One”

  1. RSVR85 says:

    Span WINDOWS…..not Widows!! :p

  2. RSVR85 says:

    Make WINDOWS, not Widows!! & isn’t this a [How To]? :p

    This guide is really handy, especially as WHS is dropping that feature!

    1. Anonymous says:

      Hope you are not referring to a spell-check error :-o ???
      oh, you are being funny… right … got it :-p

      1. RSVR85 says:

        Nope, I wasn’t being funny (i have no sense of humour), I was referring to a spelling mistake!
        Rich must have half amended it ;)

      2. Rich says:

        Yep, you got me.

  3. Taylorliles says:

    I know this is old but I have found this very helpful. I still have a question. I have a home server set up now. My problem is that I have 1tb and an 80gb on my main desktop that I want to put on the server and I want to set the server up as one big spanned volume but I have no way of backing up my data on the 1tb. I only have an 320gb on my main desktop and a 250gb on the server for the OS. Anyone have any idea? Thanks

Comments are closed.

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