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Unmount method of the Msvm_ImageManagementService class

Hyper-V

[The Unmount method is available for use in the operating systems specified in the Requirements section. It may be altered or unavailable in subsequent versions. Instead, use the Unmount method of the Msvm_MountedStorageImage class.]

Unmounts an existing virtual disk image file in loopback mode.

Syntax


uint32 Unmount(
  [in]  string Path
);

Parameters

Path [in]

Type: string

A fully qualified path that specifies the location of the virtual disk image file.

Return value

Type: uint32

This method can return one of the following values.

Completed with No Error (0)
Failed (32768)
Access Denied (32769)
Not Supported (32770)
Status is unknown (32771)
Timeout (32772)
Invalid parameter (32773)
System is in use (32774)
Invalid state for this operation (32775)
Incorrect data type (32776)
System is not available (32777)
Out of memory (32778)

Remarks

Access to the Msvm_ImageManagementService class might be restricted by UAC Filtering. For more information, see User Account Control and WMI.

Examples

The following C# example unmounts a virtual disk image file. The referenced utilities can be found in Common Utilities for the Virtualization Samples.



using System;
using System.Management;

namespace HyperVSamples
{
    class UnmountVHD
    {
        static void Unmount(string vhdPath)
        {
            ManagementScope scope = new ManagementScope(@"root\virtualization", null);
            ManagementObject imageService = Utility.GetServiceObject(scope, "Msvm_ImageManagementService");

            ManagementBaseObject inParams = imageService.GetMethodParameters("Unmount");
            inParams["Path"] = vhdPath;
            ManagementBaseObject outParams = imageService.InvokeMethod("Unmount", inParams, null);
            if ((UInt32)outParams["ReturnValue"] == ReturnCode.Completed)
            {
                Console.WriteLine("{0} was unmounted successfully.", inParams["Path"]);
            }
            else
            {
                Console.WriteLine("Unmount operation for {0} failed with error {1}.", vhdPath, outParams["ReturnValue"]);
            }

            inParams.Dispose();
            outParams.Dispose();
            imageService.Dispose();
        }

        static void Main(string[] args)
        {
            if (args != null && args.Length != 1)
            {
                Console.WriteLine("Usage: UnmountVHD vhdPath");
                return;
            }
            Unmount(args[0]);
        }
    }
}


The following VBScript example unmounts a virtual disk image file.


option explicit 

dim objWMIService
dim vhdPath
dim managementService
dim fileSystem

const wmiCompleted = 0

Main()

'-----------------------------------------------------------------
' Main
'-----------------------------------------------------------------
Sub Main()

    dim objArgs, computer
    set fileSystem = Wscript.CreateObject("Scripting.FileSystemObject")

    computer = "."
    set objWMIService = GetObject("winmgmts:\\" & computer & "\root\virtualization")
    set managementService = objWMIService.ExecQuery("Select * from Msvm_ImageManagementService").ItemIndex(0)

    set objArgs = WScript.Arguments
    if WScript.Arguments.Count = 1 then
        vhdPath = objArgs.Unnamed.Item(0)
    else
        WScript.Echo "usage: cscript unmountVHD.vbs vhdPath"
        WScript.Quit(1)
    end if


    if ExecuteUnmountVHD then
        WriteLog "Done"
        WScript.Quit(0)
    else
        WriteLog "Unmount operation failed."
        WScript.Quit(1)
    end if

End Sub

'-----------------------------------------------------------------
' ExecuteUnmountVHD
'-----------------------------------------------------------------
Function ExecuteUnmountVHD ()

    WriteLog Format1("Sub ExecuteUnmountVHD ({0})",  vhdPath)
    
    dim objInParam, objOutParams

    ExecuteUnmountVHD = false

    set objInParam = managementService.Methods_("Unmount").InParameters.SpawnInstance_()
    objInParam.Path = vhdPath

    set objOutParams = managementService.ExecMethod_("Unmount", objInParam)

    if  objOutParams.ReturnValue = wmiCompleted then
        ExecuteUnmountVHD = true
        WriteLog Format1("{0} was unmounted successfully.", vhdPath)
    else
        WriteLog Format2("Unmount operation for {0} failed with error {1}", vhdPath, objOutParams.ReturnValue)
    end if
    
End Function

'-----------------------------------------------------------------
' Create the console log files.
'-----------------------------------------------------------------
Sub WriteLog(line)
    dim fileStream
    set fileStream = fileSystem.OpenTextFile(".\UnmountVHD.log", 8, true)
    WScript.Echo line
    fileStream.WriteLine line
    fileStream.Close
End Sub

'------------------------------------------------------------------------------
' The string formatting functions to avoid string concatenation.
'------------------------------------------------------------------------------
Function Format2(myString, arg0, arg1)
    Format2 = Format1(myString, arg0)
    Format2 = Replace(Format2, "{1}", arg1)
End Function

'------------------------------------------------------------------------------
' The string formatting functions to avoid string concatenation.
'------------------------------------------------------------------------------
Function Format1(myString, arg0)
    Format1 = Replace(myString, "{0}", arg0)
End Function

Requirements

Minimum supported client

None supported

Minimum supported server

Windows Server 2008

End of client support

None supported

End of server support

Windows Server 2012

Namespace

\\.\Root\Virtualization

MOF

WindowsVirtualization.mof

See also

DetachVirtualHardDisk (V2)
Msvm_ImageManagementService

 

 

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