I've just done an in-place upgrade of a Hyper-V guest from Windows Server 2008 to Server 2012 R2 (via Server 2012, as direct upgrade from 2008 to 2012 R2 is not supported). Usually one would create a new machine and seize roles, which is Microsoft's officially "preferred" option, but for organisational reasons this isn't possible. This is a test run, on a copy of the original VM disconnected from network.
All appears okay except one of the 3 data drives (separate VHDX files) shows "Access Denied" when double-clicking to open the drive in Windows Explorer. However, I can list directories and view files from the command line!
Steps taken to resolve:
- Double checked Hyper-V guest settings exactly the same as the production server
chkdskwithin the VM, no errors found
- disk management shows healthy active primary partition (interestingly this is the only disk with unallocated space the beginning, perhaps this is relevant?)
- also relevant: the disk cannot be marked as offline, and it was previously host to the pagefile
- moved pagefile to
C:\(now the disk can be brought offline in disk management)
- took disk offline then online again
- removed drive letter assignment and re-added
- backed up shares from registry, shutdown VM, disconnected the VHDX in question, rebooted, shutdown, re-connected the VHDX
- created a new volume in the unallocated space before the volume in question on that disk, then deleted it
- re-copied the VHDX file for this drive from the production server, in case the VHDX became corrupt during the original copy
- last ditch, I took ownership and re-permissioned the drive (this folder, all subfolders and files), and applied to child objects. Still getting "Access denied", indicating it's not an ACL (file permissions) related issue
This doesn't affect any other drives, including the system drive.
I haven't yet robocopied data to a new drive as I want to understand the root cause.
What should I try next?