Exporting a snapshot of a virtual machine
The following C# and Visual Basic Scripting Edition (VBScript) samples demonstrate exporting a snapshot of a virtual machine. Samples that demonstrate exporting a virtual machine can be found on the ExportSystemDefinition topic.
The referenced C# utilities can be found in Common utilities for the virtualization samples (V2).
using System;
using System.IO;
using System.Management;
namespace HyperVSamples
{
class ExportSystemDefinitionSnapshotsClass
{
static ManagementObject GetLastVirtualSystemSnapshot(ManagementObject vm)
{
ManagementObjectCollection settings = vm.GetRelated(
"Msvm_VirtualSystemSettingData",
"Msvm_MostCurrentSnapshotInBranch",
null,
null,
"Dependent",
"Antecedent",
false,
null);
ManagementObject virtualSystemsetting = null;
foreach (ManagementObject setting in settings)
{
Console.WriteLine(setting.Path.Path);
Console.WriteLine(setting["ElementName"]);
virtualSystemsetting = setting;
}
return virtualSystemsetting;
}
static string GetVirtualSystemExportSettingDataInstance(ManagementScope scope, ManagementObject snapshotSettingData)
{
ManagementPath settingPath = new ManagementPath("Msvm_VirtualSystemExportSettingData");
ManagementClass exportSettingDataClass = new ManagementClass(scope, settingPath, null);
ManagementObject exportSettingData = exportSettingDataClass.CreateInstance();
exportSettingData["CopySnapshotConfiguration"] = 2;
exportSettingData["CreateVmExportSubdirectory"] = true;
exportSettingData["SnapshotVirtualSystem"] = snapshotSettingData.Path.Path;
string settingData = exportSettingData.GetText(TextFormat.CimDtd20);
exportSettingData.Dispose();
exportSettingDataClass.Dispose();
return settingData;
}
static void ExportSystemDefinitionSnapshots(string vmName, string exportDirectory)
{
ManagementScope scope = new ManagementScope(@"root\virtualization\v2", null);
ManagementObject virtualSystemService = Utility.GetServiceObject(scope, "Msvm_VirtualSystemManagementService");
ManagementBaseObject inParams = virtualSystemService.GetMethodParameters("ExportSystemDefinition");
ManagementObject vm = Utility.GetTargetComputer(vmName, scope);
ManagementObject snapshotSettingData = GetLastVirtualSystemSnapshot(vm);
if ( snapshotSettingData == null )
{
Console.WriteLine("There are not snapshots in the VM to be exported...");
return;
}
inParams["ComputerSystem"] = vm.Path.Path;
if (!Directory.Exists(exportDirectory))
{
Directory.CreateDirectory(exportDirectory);
}
inParams["ExportDirectory"] = exportDirectory;
inParams["ExportSettingData"] = GetVirtualSystemExportSettingDataInstance(scope, snapshotSettingData);
ManagementBaseObject outParams = virtualSystemService.InvokeMethod("ExportSystemDefinition", inParams, null);
if ((UInt32)outParams["ReturnValue"] == ReturnCode.Started)
{
if (Utility.JobCompleted(outParams, scope))
{
Console.WriteLine("VM '{0}' were exported successfully.", vm["ElementName"]);
}
else
{
Console.WriteLine("Failed to export VM");
}
}
else if ((UInt32)outParams["ReturnValue"] == ReturnCode.Completed)
{
Console.WriteLine("VM '{0}' were exported successfully.", vm["ElementName"]);
}
else
{
Console.WriteLine("Export virtual system failed with error:{0}", outParams["ReturnValue"]);
}
inParams.Dispose();
outParams.Dispose();
vm.Dispose();
virtualSystemService.Dispose();
}
static void Main(string[] args)
{
if (args != null && args.Length != 2)
{
Console.WriteLine("Usage: ExportSystemDefinitionSnapshots vmName exportDirectory");
return;
}
ExportSystemDefinitionSnapshots(args[0], args[1]);
}
}
}
option explicit
dim objWMIService
dim managementService
dim fileSystem
const JobStarting = 3
const JobRunning = 4
const JobCompleted = 7
const wmiStarted = 4096
const wmiSuccessful = 0
Main()
'-----------------------------------------------------------------
' Main
'-----------------------------------------------------------------
Sub Main()
dim computer, objArgs, vmName, vm, exportDirectory
set fileSystem = Wscript.CreateObject("Scripting.FileSystemObject")
computer = "."
set objWMIService = GetObject("winmgmts:\\" & computer & "\root\virtualization\v2")
set managementService = objWMIService.ExecQuery("select * from Msvm_VirtualSystemManagementService").ItemIndex(0)
set objArgs = WScript.Arguments
if WScript.Arguments.Count = 2 then
vmName = objArgs.Unnamed.Item(0)
exportDirectory = objArgs.Unnamed.Item(1)
else
WScript.Echo "usage: cscript ExportSystemDefinitionSnapshots.vbs vmName exportDirectoryName"
WScript.Quit(1)
end if
set vm = GetComputerSystem(vmName)
if ExportSystemDefinitionSnapshots(vm, exportDirectory) then
WriteLog "Done"
WScript.Quit(0)
else
WriteLog "ExportSystemDefinitionSnapshots Failed."
WScript.Quit(1)
end if
End Sub
'-----------------------------------------------------------------
' Retrieve Msvm_VirtualComputerSystem from base on its ElementName
'-----------------------------------------------------------------
Function GetComputerSystem(vmElementName)
On Error Resume Next
dim query
query = Format1("select * from Msvm_ComputerSystem where ElementName = '{0}'", vmElementName)
set GetComputerSystem = objWMIService.ExecQuery(query).ItemIndex(0)
if (Err.Number <> 0) then
WriteLog Format1("Err.Number: {0}", Err.Number)
WriteLog Format1("Err.Description:{0}",Err.Description)
WScript.Quit(1)
end if
End Function
'-----------------------------------------------------------------
' Get Last Snapshot of a Virtual System
'-----------------------------------------------------------------
Function GetLastVirtualSystemSnapshot(computerSystem, snapshot)
dim objVSSDs, vssd
dim query
GetLastVirtualSystemSnapshot = false
query = Format1("ASSOCIATORS OF {{0}} WHERE resultClass = Msvm_VirtualSystemsettingData", computerSystem.Path_.Path)
set objVSSDs = objWMIService.ExecQuery(query)
for each vssd in objVSSDs
if vssd.SettingType = 5 then 'SettingType = 5 means it is a snapshot
GetLastVirtualSystemSnapshot = true
set snapshot = vssd
end if
next
End Function
'-----------------------------------------------------------------
' Export a virtual system
'-----------------------------------------------------------------
Function ExportSystemDefinitionSnapshots(computerSystem, exportDirectory)
dim objInParam, objOutParams
dim query
dim computer
dim exportSettingData
dim lastSnapshot
dim isSnapshotPresent
ExportSystemDefinitionSnapshots = false
if Not fileSystem.FolderExists(exportDirectory) then
fileSystem.CreateFolder(exportDirectory)
end if
set objInParam = managementService.Methods_("ExportSystemDefinition").InParameters.SpawnInstance_()
objInParam.ComputerSystem = computerSystem.Path_.Path
query = Format1("ASSOCIATORS OF {{0}} WHERE resultClass = Msvm_VirtualSystemExportSettingData", computerSystem.Path_.Path)
set exportSettingData = objWMIService.ExecQuery(query).ItemIndex(0)
exportSettingData.CopyVmStorage = true
exportSettingData.CopyVmRuntimeInformation = true
exportSettingData.CreateVmExportSubdirectory = true
exportSettingData.CopySnapshotConfiguration = 2
isSnapshotPresent = GetLastVirtualSystemSnapshot(computerSystem, lastSnapshot)
if isSnapshotPresent = false then
WriteLog "No snapshots were found on the VM when trying to export snapshot as VM."
ExportSystemDefinitionSnapshots = false
Exit Function
end if
exportSettingData.SnapshotVirtualSystem = lastSnapshot.Path_.Path
objInParam.ExportSettingData = exportSettingData.GetText_(1)
objInParam.ExportDirectory = exportDirectory
set objOutParams = managementService.ExecMethod_("ExportSystemDefinition", objInParam)
if objOutParams.ReturnValue = wmiStarted then
if (WMIJobCompleted(objOutParams)) then
ExportSystemDefinitionSnapshots = true
end if
elseif (objOutParams.ReturnValue = wmiSuccessful) then
ExportSystemDefinitionSnapshots = true
else
WriteLog Format1("ExportSystemDefinitionSnapshots failed with ReturnValue {0}", objOutParams.ReturnValue)
end if
End Function
'-----------------------------------------------------------------
' Handle wmi Job object
'-----------------------------------------------------------------
Function WMIJobCompleted(outParam)
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(".\ExportSystemDefinition-ExportSnapshot.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