When you use shared virtual hard disk (.vhdx) files on a Windows Server 2012 R2 computer, Windows OS may experience memory leak. For every IO issued by svhdxflt, VHDMP believes that there is an Activity ID. VHDMP enables this Activity ID tracing which results in the unnecessary nonpaged pool memory usage.
Note For the shared .vhdx of the Cluster Shared Volume (CSV), the memory leak may occur on the Hyper-V server that hosts the Virtual Machine (VM). For the shared .vhdx of the Scale-Out File Server, the memory leak may occur on the server (node) in Scale-Out File Server cluster that hosts the .vhdx file.
To resolve this issue, install update 2919355. For more information about how to obtain update 2919355, click the following article number to view the article in the Microsoft Knowledge Base:
2919355 Windows RT 8.1, Windows 8.1, and Windows Server 2012 R2 Update April, 2014
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
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