ValidateVirtualHardDisk method of the Msvm_ImageManagementService class

Validates whether a virtual disk image can be opened in read-only mode.

Syntax

uint32 ValidateVirtualHardDisk(
  [in]  string              Path,
  [out] CIM_ConcreteJob REF Job
);

Parameters

Path [in]

Type: string

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

Job [out]

Type: CIM_ConcreteJob

A reference to the job (can be null if the task is completed successfully).

Return value

Type: uint32

This method can return one of the following values.

Remarks

If the virtual hard disk is a differencing disk, the entire virtual disk chain is opened. If the link is broken in the disk chain, a job object is returned with the appropriate error initialized and the child and parent properties are initialized to the location where the link is broken.

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 validates a virtual hard disk image. The referenced utilities can be found in Common Utilities for the Virtualization Samples.

using System;
using System.Management;

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

            ManagementBaseObject inParams = imageService.GetMethodParameters("ValidateVirtualHardDisk");
            inParams["Path"] = vhdPath;
            ManagementBaseObject outParams = imageService.InvokeMethod("ValidateVirtualHardDisk", inParams, null);
            if ((UInt32)outParams["ReturnValue"] == ReturnCode.Started)
            {
                if (Utility.JobCompleted(outParams, scope))
                {
                    Console.WriteLine("{0} is a valid virtual hard disk.", inParams["Path"]);
                }
                else
                {
                    Console.WriteLine("Unable to validate {0}", inParams["Path"]);
                }
            }

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

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

    }
}

The following VBScript example validates a virtual hard disk image.

option explicit 

dim objWMIService
dim managementService
dim fileSystem
dim vhdPath

const JobStarting = 3
const JobRunning = 4
const JobCompleted = 7
const wmiStarted = 4096


Main()

'-----------------------------------------------------------------
' Main
'-----------------------------------------------------------------
Sub Main()
    set fileSystem = Wscript.CreateObject("Scripting.FileSystemObject")
    dim computer, objArgs
    
    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 ValidateVHD.vbs path"
        WScript.Quit(1)
    end if

    if ValidateVHD(vhdPath) then
        WriteLog "Done"
        WScript.Quit(0)
    else
        WriteLog "ValidateVHD failed"
        WScript.Quit(1)
    end if


End Sub

'-----------------------------------------------------------------
' Execute ValidateVirtualHardDisk
'-----------------------------------------------------------------
Function ValidateVHD(vhdPath)
    WriteLog Format1("Function ValidateVHD({0})",  vhdPath)
    dim objInParam, objOutParams

    ValidateVHD = false

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

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

    if (WMIMethodStarted(objOutParams)) then
        if (WMIJobCompleted(objOutParams)) then
            WriteLog Format1("{0} is a valid virtual hard disk.", vhdPath)
            ValidateVHD = true
        end if
    end if

End Function


'-----------------------------------------------------------------
' Handle wmi return values
'-----------------------------------------------------------------
Function WMIMethodStarted(outParam)
    WriteLog "Function WMIMethodStarted"
    
    dim wmiStatus
    
    WMIMethodStarted = false

    if Not IsNull(outParam) then
        wmiStatus = outParam.ReturnValue

        if  wmiStatus = wmiStarted then
            WMIMethodStarted = true
        else
            WriteLog Format1("Unable to validate {0}", vhdPath)
        end if
   end if

End Function

'-----------------------------------------------------------------
' Handle wmi Job object
'-----------------------------------------------------------------
Function WMIJobCompleted(outParam)
    WriteLog "Function WMIJobCompleted"
    dim WMIJob, jobState

    set WMIJob = objWMIService.Get(outParam.Job)

    WMIJobCompleted = true

    jobState = WMIJob.JobState

    while jobState = JobRunning or jobState = JobStarting
        WriteLog Format1("In progress... {0}% completed.",WMIJob.PercentComplete)
        WScript.Sleep(1000)
        set WMIJob = objWMIService.Get(outParam.Job)
        jobState = WMIJob.JobState
    wend

    if (jobState <> JobCompleted) then
        WriteLog Format1("ErrorCode:{0}", WMIJob.ErrorCode)
        WriteLog Format1("ErrorDescription:{0}", WMIJob.ErrorDescription)
        WMIJobCompleted = false
    end if

End Function

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

End Sub


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

Requirements

See also

ValidateVirtualHardDisk (V2)

CIM_ConcreteJob

Msvm_ImageManagementService