[UPDATE : This only works for build 9841. Any newer build (Current : 9860) not applicable by below instruction.]
Without further checking, I had perform in-place upgrade of my current Win8.1 Enterprise into Windows 10 for Enterprise Technical Preview!
But straight away my Hyper-V VM failed to turn on with error, Synthetic SCSI Controller has no permission to access. This was due to Dedup-ed volume is not accessible without first enabling Deduplication on that particular volume.
A quick browse to 365lab.net quickly returned the method to enable Deduplication in Windows 10! Again, big thanks to Author Johan for these files.
Download the files from OneDrive and extract with 7-zip, and run following command in PowerShell.
dism /online /add-package /packagepath:Microsoft-Windows-VdsInterop-Package~31bf3856ad364e35~amd64~~6.4.9841.0.cab /packagepath:Microsoft-Windows-VdsInterop-Package~31bf3856ad364e35~amd64~en-US~6.4.9841.0.cab /packagepath:Microsoft-Windows-FileServer-Package~31bf3856ad364e35~amd64~~6.4.9841.0.cab /packagepath:Microsoft-Windows-FileServer-Package~31bf3856ad364e35~amd64~en-US~6.4.9841.0.cab /packagepath:Microsoft-Windows-Dedup-Package~31bf3856ad364e35~amd64~~6.4.9841.0.cab /packagepath:Microsoft-Windows-Dedup-Package~31bf3856ad364e35~amd64~en-US~6.4.9841.0.cab
dism /online /enable-feature /featurename:Dedup-Core /all
Right after this would be the usual command to enable Deduplication features on volume:
#Enable Deduplication for a specific volume
Enable-DedupVolume -Volume D:
#Enable Deduplication for open files
Set-DedupVolume -Volume D: -OptimizeInUseFiles
#Force a Deduplication job on the volume
Start-DedupJob -Volume D: -Type Optimization
#Check deduplication status on the volume
Get-DedupVolume -Volume D:
That’s it! Enjoy.