In this article we will look at an issue related to Storage Live Migration in Windows Server 2012 R2, where the source VHD/VHDX-files is not deleted when the migration completes.

A while ago we started noticing at several customers and our own lab-environment that source VHD/VHDX-files was not deleted when the migration completes. In the Hyper-V Virtual Machine Management Service (VMMS) event log on the Hyper-V host where the virtual machine is running, event 20878 was logged with the error Failed to delete file ‘<Path to VHD/VHDX-file>’: ‘General access denied error'(‘0x80070005’):


To reproduce the problem, create a new virtual machine and perform a Storage Live Migration. A strange behavior we noticed is that the issue is not present on subsequent Storage Live Migrations of the same virtual machine.

After troubleshooting the issue for a while we opened a support case with Microsoft, who eventually advised us to uninstall the following hotfix:

KB2966407 – Backing up virtual machines fails when using the CSV writer after installation of update 2919355 in Windows

The issue seems to be resolved after uninstalling the hotfix. The current status is reported back to the Hyper-V development team, and we would expect an upcoming hotfix to resolve the issue without needing to uninstall KB2966407.

This article will be updated when new information is available.

Jan Egil Ring works as a Lead Architect on the Infrastructure Team at Crayon, Norway. He mainly works with Microsoft server-products and has a strong passion for Windows PowerShell. In addition to being a consultant, he is a Microsoft Certified Trainer. He has obtained several certifications such as MCSE: Server Infrastructure and MCSE: Private Cloud. He is also a multiple-year recipient of the Microsoft Most Valuable Professional Award for his contributions in the Windows PowerShell technical community.


    • Personally I always verify that the running virtual machine is using the destination VHDX before deleting the source VHDX. When this is done, it is safe to delete the source VHDX.

  1. Is there is any update on this. I unable to find details for uninstalling hotfix to fix the issue. Can you please share if you have any MS article for this issue

  2. I have found a work around for this..just move the CSV the files reside on to a different host…after this the files will be gone

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