V-79-57344-38721 - 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

Problem

When performing Hyper-V Agent GRT (Granular Recovery Technology) 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

V-79-57344-38721 - Failed to mount one or more virtual disk images. Restores that use Granular Recovery Technology may not be available from this backup set.

Cause

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.

Information about Microsoft support policy for large-sector drives in Windows
http://support.microsoft.com/kb/2510009

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)
 

Solution

WORKAROUND

• 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. 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

Hyper-V Agent
Restore from Tape.