Enable Data deduplication in Windows 8.1

Note : The procedure below is not officially supported on Windows 8.1, it can break your Windows installation!

On of the new features that came out with Windows Server 2012 last year was data deduplication, a feature which can save GB’s of space on your servers. After a couple of weeks there was also a way to ‘enable’ the data deduplication feature on your Windows 8 client. This Friday (Oct. 18th) Windows Server 2012 R2 and Windows 8.1 will be generally available. And the procedure to enable data deduplication on Windows 8.0 also works with Windows 8.1!

Follow the steps below to install and enable the feature and save a lot of (SSD) space on your laptop!

  1. Download the installation files and unzip them.
  2. Open an admin command prompt and browse to the folder where you unzipped the files.
  3. Run the included install.cmd to add the feature to your Windows 8.1 client.
  4. Go to the Windows 8.1 Start Screen and type Turn Windows Features. Select Turn Windows features on or off.
    You can see that Data Deduplication is already enabled. Click OK.
  5. Open a PowerShell cmd and type the following command to enable data deduplication on the drive / partition:
    Enable-DedupVolume –Volume D:   (where D: is the volume for which you want to enable data deduplication)
  6. To start the deduplication process use the following command:
    Start-DedupJob -Volume D: -Type Optimization (where D: is the volume for which you want to enable data deduplication)
  7. Repeat step 5 and 6 for every volume you want to deduplicate.
  8. To check the status of the deduplication process use the following command:
    In the example above you can see that data deduplication saved 68 GB on both of my volumes!
  • Henrik Bierbum Bacher

    The command in the 6. step should be: Start-DedupJob -Volume D: -Type Optimization

    • Thanks, you’re correct!

  • JasonW

    How do you determine what files are needed from the Server image so you can install the role on the client OS?

  • cdecker

    Is it right, that you cannot use Dedup on the OS-Partition ?

    • joed


  • BeefNeegroidMaster

    This does not work on Windows 8.1 Update 1. Any fix? Thanks!

  • Robert_IT

    You should add the “FACT” that if you reinstall your OS you will not be able to access the de- duplicated volume until you add these settings back to the system. After doing this successfully once on Windows 8 I feel it’s TOO RISKY to attempt anymore.
    If you find yourself hosed DO NOT DELETE the volume. If necessary, install an evaluation version of Server 2012 R2 and enable deduplication to access your data. Also, having additional backups of your critical data is paramount before attempting this.


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