MergeVirtualHardDisk method of the Msvm_ImageManagementService class
Merges a differencing virtual hard disk file with its parents. If the user executing this function does not have permission to update the virtual machines, then this function will fail.
Syntax
uint32 MergeVirtualHardDisk(
[in] string SourcePath,
[in] string DestinationPath,
[out] CIM_ConcreteJob REF Job
);
Parameters
-
SourcePath [in]
-
Type: string
A fully qualified path that specifies the location of the merging file.
-
DestinationPath [in]
-
Type: string
A fully qualified path that specifies the location of the parent disk image file into which data is to be merged. This could be the immediate parent virtual disk image of the merging file or parent disk image few levels up the differencing drive chain.
-
Job [out]
-
Type: CIM_ConcreteJob
A reference to the job (can be null if the task is completed).
Return value
Type: uint32
This method can return one of the following values.
-
Completed with No Error (0)
-
Method Parameters Checked - Job Started (4096)
-
Failed (32768)
-
Access Denied (32769)
-
Not Supported (32770)
-
Status is unknown (32771)
-
Timeout (32772)
-
Invalid parameter (32773)
-
System is in used (32774)
-
Invalid state for this operation (32775)
-
Incorrect data type (32776)
-
System is not available (32777)
-
Out of memory (32778)
-
File not found (32779)
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 merges a differencing virtual hard disk file. The referenced utilities can be found in Common Utilities for the Virtualization Samples.
using System;
using System.Management;
namespace HyperVSamples
{
class MergeVHD
{
static void MergeVirtualHardDisk(string sourcePath, string destinationPath)
{
ManagementScope scope = new ManagementScope(@"root\virtualization", null);
ManagementObject imageService = Utility.GetServiceObject(scope, "Msvm_ImageManagementService");
ManagementBaseObject inParams = imageService.GetMethodParameters("MergeVirtualHardDisk");
inParams["SourcePath"] = sourcePath;
inParams["DestinationPath"] = destinationPath;
ManagementBaseObject outParams = imageService.InvokeMethod("MergeVirtualHardDisk", inParams, null);
if ((UInt32)outParams["ReturnValue"] == ReturnCode.Started)
{
if (Utility.JobCompleted(outParams, scope))
{
Console.WriteLine("{0} was merged successfully.", inParams["SourcePath"]);
}
else
{
Console.WriteLine("Unable to merge {0}", inParams["SourcePath"]);
}
}
inParams.Dispose();
outParams.Dispose();
imageService.Dispose();
}
static void Main(string[] args)
{
if (args != null && args.Length != 2)
{
Console.WriteLine("Usage: MergeVHD SourcePath, DestinationPath");
return;
}
MergeVirtualHardDisk(args[0], args[1]);
}
}
}
The following VBScript example merges a differencing virtual hard disk file.
option explicit
dim objWMIService
dim managementService
dim fileSystem
const JobStarting = 3
const JobRunning = 4
const JobCompleted = 7
const wmiStarted = 4096
const method = ""
Main()
'-----------------------------------------------------------------
' Main
'-----------------------------------------------------------------
Sub Main()
dim sourcePath, destinationPath, computer, objArgs
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 = 2 then
sourcePath = objArgs.Unnamed.Item(0)
destinationPath = objArgs.Unnamed.Item(1)
else
WScript.Echo "usage: cscript ConvertVHD.vbs sourcePath destinationPath"
WScript.Quit(1)
end if
if MergeVirtualHardDisk(sourcePath, destinationPath) then
WriteLog "Done"
WScript.Quit(0)
else
WriteLog "ConvertVHD failed"
WScript.Quit(1)
end if
End Sub
'-----------------------------------------------------------------
' Execute MergeVirtualHardDisk
'-----------------------------------------------------------------
Function MergeVirtualHardDisk(sourcePath, destinationPath)
WriteLog Format2("Sub MergeVirtualHardDisk({0}, {1})", sourcePath, DestinationPath)
dim objInParam, objOutParams
MergeVirtualHardDisk = false
set objInParam = managementService.Methods_("MergeVirtualHardDisk").InParameters.SpawnInstance_()
objInParam.SourcePath = SourcePath
objInParam.DestinationPath = DestinationPath
set objOutParams = managementService.ExecMethod_("MergeVirtualHardDisk", objInParam)
if (WMIMethodStarted(objOutParams)) then
if (WMIJobCompleted(objOutParams)) then
WriteLog Format2("'{0}' was successfully merged into '{1}'.", sourcePath, destinationPath)
MergeVirtualHardDisk = 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("Merge operation failed to create ConcreteJob with error {2}", wmiStatus)
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(".\MergeVHD.log", 8, true)
WScript.Echo line
fileStream.WriteLine line
fileStream.Close
End Sub
'------------------------------------------------------------------------------
' The string formatting functions to avoid string concatenation.
'------------------------------------------------------------------------------
Function Format3(myString, arg0, arg1, arg2)
Format3 = Format2(myString, arg0, arg1)
Format3 = Replace(Format3, "{2}", arg2)
End Function
'------------------------------------------------------------------------------
' 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 |
|