Hyper-V GRT restore fails with "Failed to mount one or more virtual disk images" if staging location resides on an advanced format 4k sector disk drives


When performing Hyper-V Agent GRT restore from Tape the job may fail with the following error when the staging location is a Advanced Format 4K Sector disk drives. 

When Backup Exec performs a Hyper-V Agent GRT restore from tape the data must be staged to a local disk on the Backup Exec media server. If the staging location specified in the job or Backup Exec settings is on a Advanced Format 4K Sector disk drives the job will fail to mount the VHD files.


Error Message

Failed to mount one or more virtual disk images. Restores that use Granular Recovery Technology may not be available from this backup set.




In order to perform a GRT restore from tape  Backup Exec must be able to mount the VHD files on the Backup Exec media server Staging location.  Due to Microsoft limitations Backup Exec is unable mount and access VHD files on Advanced Format 4K Sector drives or volumes. See Additional Microsoft Links below.

Using Hyper-V with large sector drives on Windows Server 2008 and Windows
Server 2008 R2

Information about Microsoft support policy for large-sector drives in Windows

To determine if the drive is Advanced Format 4K Sector Run the following command from elevated command prompt:
Fsutil fsinfo ntfsinfo x: (where x: represents the drive that you are checking)




  • Change the Staging location to a drive with native 512 sector size or 512e Emulation.
  • Format the Staging location drive to support 512 sector size or 512e Emulation if possible.
  • Redirect restore the Virtual machine to a non-4k sector drive on a Windows 2008 R2 server. Mount the VHD files in Disk Management and retrieve the files needed.
  • Redirect restore the entire virtual machine back to the Hyper-v host.

 See Related Documents


Applies To

Backup Exec 2012

Hyper-V Agent

Restore from Tape.


Terms of use for this information are found in Legal Notices.



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