When Windows Server 2016 was released, Data Deduplication was not available for ReFS file system, and only available for NTFS. With Windows Server 2019, data deduplication is now available for both NTFS and ReFS file systems.

Data Deduplication is a great technology that allows you to reduces your storage footprint by removing any duplicated data blocks and replacing it with metadata.

In the scenario below, I will show you how to enable Data Deduplication and tracking the ‘saving rate’ of the data deduplication.

Install-WindowsFeature FS-Data-Deduplication

This cmdlet will allow you to install the feature. In most scenarios, ie. Storage Spaces Direct, Hyper-V, this will make most sense. Also, this cmdlet would need to be executed on all nodes.

Get-Command *Dedup*

Now that we have data deduplication installed, we can now see all the of the cmdlets available.

Enable-DedupVolume -Volume "E:","F:" -UsageType HyperV

Finally, once we enable data deduplication on the volumes, we can now track the saving rate. Note, this can be done via PowerShell, or Windows Admin Center (WAC). Note, this can only be enabled on Cluster Shared Volumes (CSV).

Get-DedupVolume

I hope this helps, and now you can start minimizing the data deduplication within your environment.