I am having an issue with Server 2008 R2 not unmounting removable drives or even DVD drives when they are ejected. I discovered this because Unitrends was failing to backup an unmounted volume. The GUID for this drive shows up in the list of available drives to back up in the Unitrends interface and whether you set it as an exclusion or not Unitrends will try to back it up. Running the Poweshell command Get-WmiObject -class Win32_Volume | select-object DriveLetter, DeviceID | format-list my DVD drive will show up as mounted even though there is no disk in the drive. Scary ghost stuff going on here. Anyone experienced anything like this?
I thought it might have been VirtualClone drive, but I am not sure how to validate that other than mounting an ISO.