I have installed the Data Deduplication role on Windows Server 2016. Per Microsoft, it's using NTFS compression to help save space:

Data deduplication stores more data in less physical space. It achieves greater storage efficiency than was possible by using features such as Single Instance Storage (SIS) or NTFS compression. https://technet.microsoft.com/en-us/library/hh831602(v=ws.11).aspx

  1. Should I also enable NTFS compression in the volume's properties (see screenshot below)? Would there be any benefit?

  2. What if it was already checked? Should I uncheck it? Would there be any negative effects of having it checked?


1 Answer 1


You should not compress volumes where you plan to use deduplication.

Microsoft Knowledge Base article Files are corrupted on deduplicated volumes that were created as NTFS-compressed states:-

...deduplication metadata that is stored on the compressed volume root becomes corrupted when a process writes in-place to a file on the deduplicated volume.


To resolve this problem, do not enable data deduplication on an NTFS volume that has volume-level compression enabled.

The article goes on to list steps to disable compression on the deduplication metadata folders where the problem occurs.

It seems that you can enable NTFS folder level compression and this "works as expected" but as the deduplication does compress content anyway I would expect gains to be limited and recommend you set up some test volumes and test with a subset of your data to be sure.

  • 1
    Note: I deleted and replaced my previous answer rather than edit as it was not correct. Jan 23, 2017 at 11:40
  • Curious about this information in context of the ReFS update for Windows Server 2019 (see my question here).
    – ylluminate
    Apr 24, 2020 at 18:14
  • @ylluminate - I don't know how ReFS handles the deduplication metadata, so I wouldn't want to try to guess May 3, 2020 at 10:56

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