Deduplication filter marks files as deleted incorrectly and data corruption occurs on Windows Server 2012 R2 file server

This article describes an issue in which deduplication filter marks files as deleted incorrectly and data corruption occurs on Windows Server 2012 R2-based file server. Before you install this update, see the Prerequisites section.
This issue occurs when all the following conditions are true: 
  • One or more hard links are linked to a deduplication file.
  • One of the hard link names is overwritten by using FileLinkInformation or FileRenameInformation.
  • Sufficient contention in the system that causes the rename operation to be very slow.
  • An optimization job that re-optimizes the file when the rename operation is running.
How to get this update
Important If you install a language pack after you install this update, you must reinstall this update. Therefore, we recommend that you install any language packs that you need before you install this update. For more information, see Add language packs to Windows.

Method 1: Windows Update

This update is provided as a Recommended update on Windows Update. For more information on how to run Windows Update, see How to get an update through Windows Update.

Method 2: Microsoft Download Center

The following files are available for download from the Microsoft Download Center:
Operating systemUpdate
All supported x64-based versions of Windows Server 2012 R2DownloadDownload the package now.

For more information about how to download Microsoft support files, select the following article number to view the article in the Microsoft Knowledge Base:
119591 How to obtain Microsoft support files from online services
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Update detail information


To install this update, you should first install April 2014, update rollup for Windows RT 8.1, Windows 8.1, and Windows Server 2012 R2 (2919355) in Windows Server 2012 R2.

Registry information

To apply this update, you don't have to make any changes to the registry.

Restart requirement

You may have to restart the computer after you apply this update.

Update replacement information

This update doesn't replace a previously released update.
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
Learn about the terminology that Microsoft uses to describe software updates.
File Information
The English (United States) version of this software update installs files that have the attributes that are listed in the following tables.

Windows Server 2012 R2

  • The files that apply to a specific product, milestone (RTM, SPn), and service branch (LDR, GDR) can be identified by examining the file version numbers as shown in the following table:
    VersionProductMilestoneService branch
    6.3.960 0.18 xxxWindows Server 2012 R2RTMGDR
  • GDR service branches contain only those fixes that are widely released to address widespread, critical issues. LDR service branches contain hotfixes in addition to widely released fixes.
  • The MANIFEST files (.manifest) and the MUM files (.mum) that are installed for each environment are listed in the "Additional file information" section. MUM, MANIFEST, and the associated security catalog (.cat) files, are very important to maintain the state of the updated components. The security catalog files, for which the attributes are not listed, are signed with a Microsoft digital signature.
x64 Windows Server 2012 R2
File nameFile versionFile sizeDateTimePlatform

Additional file information

x64 Windows Server 2012 R2
File propertyValue
File nameAmd64_a16830b0724426e6b005532b87d88ae6_31bf3856ad364e35_6.3.9600.18221_none_57af5b1d7551ee54.manifest
File versionNot applicable
File size704
Date (UTC)29-Jan-2016
Time (UTC)22:04
PlatformNot applicable
File nameAmd64_microsoft-windows-dedup-filter_31bf3856ad364e35_6.3.9600.18221_none_f90da1d32b814533.manifest
File versionNot applicable
File size7,224
Date (UTC)28-Jan-2016
Time (UTC)19:49
PlatformNot applicable
File nameUpdate.mum
File versionNot applicable
File size1,574
Date (UTC)29-Jan-2016
Time (UTC)22:04
PlatformNot applicable
Note This is a "FAST PUBLISH" article created directly from within the Microsoft support organization. The information contained herein is provided as-is in response to emerging issues. As a result of the speed in making it available, the materials may include typographical errors and may be revised at any time without notice. See Terms of Use for other considerations.

Article ID: 3138865 - Last Review: 04/12/2016 20:27:00 - Revision: 2.0

Windows Server 2012 R2 Datacenter, Windows Server 2012 R2 Standard, Windows Server 2012 R2 Essentials, Windows Server 2012 R2 Foundation

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