Data loss occurs when a Windows Server 2012-based computer that has the data deduplication feature enabled crashes

Applies to: Windows Server 2012 StandardWindows Server 2012 StandardWindows Server 2012 Datacenter

Symptoms


Assume that you have a Windows Server 2012-based computer that has the data deduplication feature enabled on some volumes. When the computer crashes, data loss occurs unexpectedly. 

Cause


This issue occurs because a reparse point is set before all the deduplication data recalls are completed. The data deduplication feature recalls a section of a file to write to by using a writing process. Then, the feature flushes the written data from the recalled section to a reparse point. However, when lots of writing processes are running at the same time, the flush may be performed before all the recalls are completed. Therefore, when the computer crashes, the data that was written to the unflushed recalls is lost.

Resolution


To resolve this issue, install update rollup 2889784, or install the hotfix that is described in this article.

Update information

For more information about how to obtain update rollup 2889784, click the following article number to view the article in the Microsoft Knowledge Base:
2889784 Windows RT, Windows 8, and Windows Server 2012 update rollup: November 2013

Status


Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.

More Information


For more information about software update terminology, click the following article number to view the article in the Microsoft Knowledge Base:
824684 Description of the standard terminology that is used to describe Microsoft software updates