Step 3: Evaluate savings with the Deduplication Evaluation Tool
When the deduplication feature is installed, the Deduplication Evaluation Tool (DDPEval.exe) is automatically installed to the \Windows\System32\ directory. This tool can be copied from any Windows Server 2012 installation to systems running Windows Server 2012, Windows Server 2008 R2, or Windows 7 . You can use it to determine the expected savings that you would get if deduplication is enabled on a particular volume.
DDPEval.exe supports local drives, and it supports evaluating mapped or unmapped remote shares. The following exampleshows running DDPEval.exe by using a command syntax:
C:\> DDPEVAL.EXE \\Server\Testshare
C:\> DDPEVAL.EXE E:\Test\
C:\> DDPEVAL.EXE F:
This will produce output similar to the following:
Data Deduplication Savings Evaluation Tool
Copyright 2011-2012 Microsoft Corporation. All Rights Reserved.
Evaluated folder: E:\Test
Processed files: 34
Processed files size: 12.03MB
Optimized files size: 4.02MB
Space savings: 8.01MB
Space savings percent: 66
Optimized files size (no compression): 11.47MB
Space savings (no compression): 571.53KB
Space savings percent (no compression): 4
Files with duplication: 2
Files excluded by policy: 20
Files excluded by error: 0
When the space savings percent is calculated, you can make an informed decision to install deduplication or not.