Scans volumes for fresh data deduplication savings.


      [[-Volume] <String[]>]
      [-CimSession <CimSession[]>]
      [-ThrottleLimit <Int32>]


The Update-DedupStatus cmdlet scans one or more specified volumes to compute fresh data deduplication savings information. This cmdlet returns a DeduplicationStatus object. For quick access to cached metadata use Get-DedupStatus. When this cmdlet is run on multiple volumes with one cmdlet call, the analysis for each volume is done serially.

Note: On large volumes this cmdlet can run for several minutes and will always perform a rescan after the initial scan. The default behavior is to wait for completion, regardless of the length of time required to run the scan and rescan.

To run this cmdlet, you must start Windows PowerShell® with the Run as administrator option.

This cmdlet returns the following metadata:


Example 1: Scan a volume for savings information

PS C:\> Update-DedupStatus -Volume "D:"

This command scans the D: volume to compute data deduplication savings.

Optional Parameters


Runs the cmdlet as a background job. Use this parameter to run commands that take a long time to complete.

The cmdlet immediately returns an object that represents the job and then displays the command prompt. You can continue to work in the session while the job completes. To manage the job, use the *-Job cmdlets. To get the job results, use the Receive-Job cmdlet.

For more information about Windows PowerShell background jobs, see about_Jobs.

Default value:None
Accept pipeline input:False
Accept wildcard characters:False

Runs the cmdlet in a remote session or on a remote computer. Enter a computer name or a session object, such as the output of a New-CimSession or Get-CimSession cmdlet. The default is the current session on the local computer.

Default value:None
Accept pipeline input:False
Accept wildcard characters:False

Specifies the maximum number of concurrent operations that can be established to run the cmdlet. If this parameter is omitted or a value of 0 is entered, then Windows PowerShell® calculates an optimum throttle limit for the cmdlet based on the number of CIM cmdlets that are running on the computer. The throttle limit applies only to the current cmdlet, not to the session or to the computer.

Default value:None
Accept pipeline input:False
Accept wildcard characters:False

Specifies one or more file system volumes for which to scan and compute fresh data deduplication savings information. Enter one or more volume IDs, drive letters, or volume GUID paths. For drive letters, use the format D:. For volume GUID paths, use the format \\?\Volume{{GUID}}. Separate multiple volumes with a comma.

Aliases:Path, Name, DeviceId
Default value:None
Accept pipeline input:True (ByPropertyName)
Accept wildcard characters:False





The Microsoft.Management.Infrastructure.CimInstance object is a wrapper class that displays Windows Management Instrumentation (WMI) objects. The path after the pound sign (#) provides the namespace and class name for the underlying WMI object.