A: To see data deduplication storage details for Windows Server 2012 (formerly code-named Windows Server 8), use Windows PowerShell. Typing this command
 get-dedupstatus and formatting the output as a list displays information about the amount of space saved:

PS C:\> get-dedupstatus | fl

Volume : D:
VolumeId : \\?\Volume{284a417e-6457-11e1-b9e1-001517c4e105}\
Capacity : 1.82 TB
FreeSpace : 1.5 TB
UsedSpace : 328.72 GB
SavedSpace : 926.2 GB
SavingsRate : 76 %
OptimizedFilesCount : 42109
OptimizedFilesSize : 1.18 TB
InPolicyFilesCount : 42112
InPolicyFilesSize : 1.22 TB
LastOptimizationTime : 4/10/2012 4:45:40 AM
LastOptimizationResult : 0x00000000
LastGarbageCollectionTime :
LastGarbageCollectionResult :
LastScrubbingTime :
LastScrubbingResult :

The next level is to look at the actual metadata of data deduplication, which shows information about how data deduplication is actually being implemented on your server. Use the cmdlet
 get-dedupmetadata
which returns the output below, for example:

Volume : D:
VolumeId : \\?\Volume{284a417e-6457-11e1-b9e1-001517c4e105}\
DataChunkCount : 6585832
DataContainerCount : 287
DataChunkAverageSize : 45.56 KB
DataChunkMedianSize : 0 B
DataStoreUncompactedFreespace : 0 B
StreamMapChunkCount : 43007
StreamMapContainerCount : 12
StreamMapAverageDataChunkCount : 365
StreamMapMedianDataChunkCount : 0
StreamMapMaxDataChunkCount : 0
HotspotChunkCount : 4129
HotspotContainerCount : 1
HotspotMedianReferenceCount : 0
CorruptionLogEntryCount : 0

To see more answers about Windows Server 2012, Windows 8, virtualization, and all things IT,  click over to our FAQs page.