Data Deduplication in Windows 8.1 – How to guide

To enable this feature which is NOT supported from Microsoft, you need to grab some files from the Windows Server 2012 R2 installation before deduplication can be enabled.. -Remember, Data Deduplication requires a dedicated drive to Work.

Storage savings on VHD / VHDX files are over 80% and is just perfect for laptop invironments.

All information written worked for me and i am running deduplication on my work laptop, but use it at your own risk

The files needed can be optained here from my Skydrive (soon to be OneDrive)

-Yes it can be done by yourself, but it is not that easy, so you choose.

Place the files in a folder, and open and CMD promt as Administrator. Go into the folder where you placed to files and run this command:

dism /online /add-package / /  / /  / /

And afterwards

dism /online /enable-feature /featurename:Dedup-Core /all

Now you can see the feature enabled under Windows Features


To enable it for a specific drive (for me the D drive) run the following command in an elevated PowerShell prompt:

Enable-DedupVolume -Volume D:

Set-DedupVolume -Volume D: -OptimizeInUseFiles

To begin Deduplication process, run this:

Start-DedupJob -Volume D: -Type Optimization

When using the drive for Hyper-V VMs (test invironment only), run:

Enable-DedupVolume -Volume D: -UsageType HyperV

To se how it goes, run:


To se status and savings, run:



Get-DedupVolume -Volume D:


Remember that Data Deduplication is a Schedules service, so change the Schedules to fit your need. To se the current Schedules, run:


To change Schedules, and yes you would like to: se my post on this matter HERE

I hope this helps you in your quest to save disk Space 🙂

Data Deduplication – How to optimize on Windows

On Windows Server 2012 there is a great feature called Data Duduplication.

I´m running this feature on my hyper-v test environment and on Windows 8.1, and the disk savings when running virtual machines is fantastic!. – try Data Deduplication, it is fantastic.

Data Deduplication requires a dedicated disk to be activated, and creating a partition to dedicate does not work.

But – all Data Deduplication is done by some scheduled maintenence jobs running in the background, if you wish to change these Windows to you needs read on.

Heads up: When running on a laptop or test invironment, running these jobs in the middle of the night (default) is not an option. Soo..


How to change Data Deduplication maintenence Schedules

See all commands by running this in powershell promt: Get-Command -Module Deduplication

Or visit Technet:

See existing Schedules on your computer/server by running: Get-DedupSchedule

Open a Powershell administrator console and run the following commands:

To change the Schedules to 11 AM on weekdays and create an optimization job, run:

New-DedupSchedule -Name “WeeklyOptimization” -Type Optimization -Days Mon,Tues,Wed,Thurs,Fri -Start 12:00 -DurationHours 2

Set-DedupSchedule –Name “WeeklyScrubbing” –Type Scrubbing –Start 11:00 –DurationHours 2 –Days Mon,Tues,Wed,Thurs,Fri –Priority Normal

Set-DedupSchedule –Name “WeeklyGarbageCollection” –Type GarbageCollection –Start 11:00 –DurationHours 2 –Days Mon,Tues,Wed,Thurs,Fri –Priority Normal

If you are planning to run hyper-v VMs on this drive (currently for testing only), run this command:

Enable-DedupVolume -Volume D: -UsageType HyperV

To start the jobs manually, run these commands:

Start-DedupJob D: -Type Scrubbing

Start-DedupJob D: -Type GarbageCollection

Start-DedupJob D: -Type Optimization

To se current status on the jobs, run: Get-DedupJob


I hope that this will help you to better utilize Data Deduplication.