Deduplication – Windows Server 2012


Tonight, let’s have a loot about deduplication. Coming with Windows Server 2012, this technologie factorize datas sequences to gain space on NTFS disks (Other tha system disks).

If i may resume, it’s easy to say that’s it’s useless for databases storageor other I/O carnivorous, but for filers, archives or backups it’s perfect, you will massive space !

To start, let’s install the feature

Import-Module ServerManager
Add-WindowsFeature -name FS-Data-Deduplication
Import-Module Deduplication


And have a look a cmdlets availables

Get-Command -Module Deduplication



Cmdlet to active deduplication isEnable-DedupVolume.

Get-Help Enable-Dedupvolume



The only argument attended is the volume. To list availables volumes use this cmdlet:





Enable-DedupVolume -Volume E:



Now, deduplication is actived for the E: volume. By default, deduplication jobs are created when you activate it on a volume. You can see them with the following cmdlet.



Obviously you can edit or add jobs as you like, remeber cmdlets available with this module 😉

Now deduplication is configured, let’s have a look where deduplication databases are stored, YOU MUST Backup them, if you encounter a crash, you won’t be able to get deduped datas anymore.

Two folders have to be backup :

  • “Chunk Store”  stocké dans /System Volume Information/Dedup/ChunkStore*
  • “Dedup Configuration” stocké dans /System Volume Information/Dedup/Settings*

More information here:

To finish with deduplication, let’s launch a manual dedup job.

Start-DedupJob –Volume E: –Type Optimization


You can list jobs like this


And to see deduplication status…




If you encouter errors during access deduplicated files, you can use the following command to repair errors, Microsoft thinks about everything 😉

Start-Dedupjob -volume E: -Type -Scrubbing -Full


Hope you’ll find use about deduplication !

See ya !

More informationss: