Taylor Brown's Blog : WMI

Attaching Passthough Disks Via WMI (SCSI or IDE)

taylorb — Fri, 16 Oct 2009 20:06:02 GMT

So you want to use passthough disks with Hyper-V cool – but how do you script attaching them? Well here’s your answer… But first you need to decide if you are going to attach them to the virtual IDE controller or the virtual SCSI controller. The IDE controller is ideal if you plan to boot from the passthough disk or if your guest doesn’t support the virtual SCSI adapter (Linux), the SCSI controller is ideal if you want to add/remove storage from the virtual machine while it’s running (feature of Hyper-V R2) or if you have more than 4 disks you want to add. Attaching to SCSI or IDE is pretty similar – there are really only 1 difference I bolded it on both scripts below you just have to select the correct controller. Other than that you can either use the physical disk number for disk manager (not too bad) or if you provide a LUN ID when you create the storage (in the case of a SAN) you can use that which can be a bit more deterministic. Either way enjoy!

Attaching Passthrough Disk To IDE Controller

$HyperVGuest = "Passthough Demo"

$VMManagementService = Get-WmiObject -class "Msvm_VirtualSystemManagementService" -namespace "root\virtualization"
$Vm = Get-WmiObject -Namespace "root\virtualization" -Query "Select * From Msvm_ComputerSystem Where ElementName='$HyperVGuest'"

$VMSettingData = Get-WmiObject -Namespace "root\virtualization" -Query "Associators of {$Vm} Where ResultClass=Msvm_VirtualSystemSettingData AssocClass=Msvm_SettingsDefineState"

$VmIdeController = (Get-WmiObject -Namespace "root\virtualization" -Query "Associators of {$VMSettingData} Where ResultClass=Msvm_ResourceAllocationSettingData AssocClass=Msvm_VirtualSystemSettingDataComponent" |`
where-object {$_.ResourceSubType -eq "Microsoft Emulated IDE Controller" -and $_.Address -eq 0})

$DiskAllocationSetting = Get-WmiObject -Namespace "root\virtualization" -Query "SELECT * FROM Msvm_AllocationCapabilities WHERE ResourceSubType = 'Microsoft Physical Disk Drive'"
$DefaultHardDisk = (Get-WmiObject -Namespace "root\virtualization" -Query "Associators of {$DiskAllocationSetting} Where ResultClass=Msvm_ResourceAllocationSettingData AssocClass=Msvm_SettingsDefineCapabilities" | `
where-object {$_.InstanceID -like "*Default"})

$Disk = Get-WmiObject -Namespace "root\virtualization" -Query "select * from Msvm_DiskDrive Where DriveNumber=2"
#$Disk = Get-WmiObject -Namespace "root\virtualization" -Query "select * from Msvm_DiskDrive Where ElementName Like '%Lun 200%'"

$DefaultHardDisk.Parent = $VmIdeController.__Path
$DefaultHardDisk.Address = 0
$DefaultHardDisk.HostResource = $Disk.__PATH

$VMManagementService.AddVirtualSystemResources($VM, $DefaultHardDisk.PSBase.GetText(1)) | ProcessWMIJob $VMManagementService "AddVirtualSystemResources"

Attaching Passthrough Disk To SCSI Controller

$HyperVGuest = "Passthough Demo"

$VMSettingData = Get-WmiObject -Namespace "root\virtualization" -Query "Associators of {$Vm} Where ResultClass=Msvm_VirtualSystemSettingData AssocClass=Msvm_SettingsDefineState"

$VmScsiController = (Get-WmiObject -Namespace "root\virtualization" -Query "Associators of {$VMSettingData} Where ResultClass=Msvm_ResourceAllocationSettingData AssocClass=Msvm_VirtualSystemSettingDataComponent" | `
where-object {$_.ElementName -eq "SCSI Controller"})

$DiskAllocationSetting = Get-WmiObject -Namespace "root\virtualization" -Query "SELECT * FROM Msvm_AllocationCapabilities WHERE ResourceSubType = 'Microsoft Physical Disk Drive'"

$DefaultHardDisk = (Get-WmiObject -Namespace "root\virtualization" -Query "Associators of {$DiskAllocationSetting} Where ResultClass=Msvm_ResourceAllocationSettingData AssocClass=Msvm_SettingsDefineCapabilities" | `
where-object {$_.InstanceID -like "*Default"})

$Disk = Get-WmiObject -Namespace "root\virtualization" -Query "select * from Msvm_DiskDrive Where DriveNumber=2"

#$Disk = Get-WmiObject -Namespace "root\virtualization" -Query "select * from Msvm_DiskDrive Where ElementName Like '%Lun 200%'"

$DefaultHardDisk.Parent = $VmScsiController.__Path

$DefaultHardDisk.Address = 0
$DefaultHardDisk.HostResource = $Disk.__PATH

$VMManagementService.AddVirtualSystemResources($VM, $DefaultHardDisk.PSBase.GetText(1)) | ProcessWMIJob $VMManagementService "AddVirtualSystemResources"

Taylor Brown
Hyper-V Integration Test Lead
http://blogs.msdn.com/taylorb

VBScript Versions of The KVP Scripts

taylorb — Mon, 05 Jan 2009 21:00:00 GMT

Ben Armstrong (aka Virtual PC Guy) posted some great VBScript and PowerShell KVP scripts. These are a great edition to some of my earlier scripts (Adding Host KVP's, Adding Guest KVP's, Modifying KVP’s). Check them out if your looking for more samples.

Sending data from parent to virtual machine via KVP

Enumerating parent KVP data

Taylor Brown
Hyper-V Integration Test Lead
http://blogs.msdn.com/taylorb

PDC Teaser – Attaching a VHD to A Virtual Machine

taylorb — Tue, 14 Oct 2008 01:55:19 GMT

PDC is just around the corner now – I am giving the dry run of my talk tomorrow morning, so of course I am working on my demo’s today… Just to give you a bit of a teaser here’s one of the scripts that I am using in one of my demo’s…

This script will take a VHD and attach it to the second port of the first IDE controller, just change the address numbers and you can change where it get’s attached.

Note that I am using the ProcessWMIJob function from Hyper-V WMI: Rich Error Messages for Non-Zero ReturnValue (no more 32773, 32768, 32700…)

$vhdToMount = "c:\test.vhd"
$HyperVGuest = "ScriptTest"

$VMManagementService = Get-WmiObject -class "Msvm_VirtualSystemManagementService" -namespace "root\virtualization"
$Vm = Get-WmiObject -Namespace "root\virtualization" -Query "Select * From Msvm_ComputerSystem Where ElementName='$HyperVGuest'"
$VMSettingData = Get-WmiObject -Namespace "root\virtualization" -Query "Associators of {$Vm} Where ResultClass=Msvm_VirtualSystemSettingData AssocClass=Msvm_SettingsDefineState"
$VmScsiController = (Get-WmiObject -Namespace "root\virtualization" -Query "Associators of {$VMSettingData} Where ResultClass=Msvm_ResourceAllocationSettingData AssocClass=Msvm_VirtualSystemSettingDataComponent" | `
                        where-object {$_.ResourceSubType -eq "Microsoft Emulated IDE Controller" -and $_.Address -eq 0})

$DiskAllocationSetting = Get-WmiObject -Namespace "root\virtualization" -Query "SELECT * FROM Msvm_AllocationCapabilities WHERE ResourceSubType = 'Microsoft Synthetic Disk Drive'"
$DefaultDiskDrive = (Get-WmiObject -Namespace "root\virtualization" -Query "Associators of {$DiskAllocationSetting} Where ResultClass=Msvm_ResourceAllocationSettingData AssocClass=Msvm_SettingsDefineCapabilities" | `
                        where-object {$_.InstanceID -like "*Default"})
$DefaultDiskDrive.Parent = $VmScsiController.__Path
$DefaultDiskDrive.Address = 1
$NewDiskDrive = ($VMManagementService.AddVirtualSystemResources($Vm.__Path, $DefaultDiskDrive.PSBase.GetText(1)) | ProcessWMIJob $VMManagementService "AddVirtualSystemResources").NewResources

$DiskAllocationSetting = Get-WmiObject -Namespace "root\virtualization" -Query "SELECT * FROM Msvm_AllocationCapabilities WHERE ResourceSubType = 'Microsoft Virtual Hard Disk'"
$DefaultHardDisk = (Get-WmiObject -Namespace "root\virtualization" -Query "Associators of {$DiskAllocationSetting} Where ResultClass=Msvm_ResourceAllocationSettingData AssocClass=Msvm_SettingsDefineCapabilities" | `
                        where-object {$_.InstanceID -like "*Default"})

$DefaultHardDisk.Parent = $NewDiskDrive
$DefaultHardDisk.Connection = $vhdToMount

$VMManagementService.AddVirtualSystemResources($Vm.__Path, $DefaultHardDisk.PSBase.GetText(1)) | ProcessWMIJob $VMManagementService "AddVirtualSystemResources"

Taylor Brown
Hyper-V Integration Test Lead
http://blogs.msdn.com/taylorb

Open Source PowerShell Editor -- PowerGUI

taylorb — Fri, 22 Aug 2008 18:53:00 GMT

Many of you know I have been a fan of PowerShellPlus for quite a while, but I was turned on to a new editor the other day that’s pretty slick – PowerGUI. Winner of this years Windows IT Pro Magazine’s Best of Tech Ed IT Pro Breakthrough Product Award this editor/GUI is not to shabby… The editor and debugger are fast and the auto compleate works pretty good – the only thing it’s missing as a copy as html (how do you think I post those samples!). The other cool thing PowerGUI sports is a nice library plugin model – when you install it you can chose to download and install many of the Quest libraries such as Active Directory management but there’s about 50 libraries listed on the PowerGUI site (none for Hyper-V yet hint hint).

Taylor Brown
Hyper-V Integration Test Lead
http://blogs.msdn.com/taylorb

Hyper-V WMI: What VHD’s/Physical Disks Are Associated With a Virtual Machine?

taylorb — Fri, 22 Aug 2008 05:10:42 GMT

I got a great question based on yesterday’s post (by the way my e-mail was blocking a lot of external messages that’s fixed now so I apologize to anyone I missed a mail from). The person was asking how they could figure out what physical disk a virtual machine is using when configured for passthough on the host… Well here’s the magic – I took it a little further and got the path’s for any attached VHD’s… Enjoy!

$HyperVParent = "localhost"
$HyperVGuest = "My Virtual Machine"

$VMManagementService = Get-WmiObject -class "Msvm_VirtualSystemManagementService" -namespace "root\virtualization" -ComputerName $HyperVParent
$Vm = Get-WmiObject -Namespace "root\virtualization" -ComputerName $HyperVParent -Query "Select * From Msvm_ComputerSystem Where ElementName='$HyperVGuest'"
$VMSettingData = Get-WmiObject -Namespace "root\virtualization" -Query "Associators of {$Vm} Where ResultClass=Msvm_VirtualSystemSettingData AssocClass=Msvm_SettingsDefineState" -ComputerName $HyperVParent

#
#Getting the Path's for Attached VHD's
$VirtualDiskResource = Get-WmiObject -Namespace "root\virtualization" `
    -Query "Associators of {$VMSettingData} Where ResultClass=Msvm_ResourceAllocationSettingData AssocClass=Msvm_VirtualSystemSettingDataComponent" `
    -ComputerName $HyperVParent | Where-Object { $_.ResourceSubType -match "Microsoft Virtual Hard Disk" }

ForEach-Object -InputObject $VirtualDiskResource -Process {
    Write-Host "Virtual Hard Disk At: $_.Connection[0]"
}

#
#Getting the Disk Attachments for Passthrough Disks
$PhysicalDiskResource = Get-WmiObject -Namespace "root\virtualization" `
    -Query "Associators of {$VMSettingData} Where ResultClass=Msvm_ResourceAllocationSettingData AssocClass=Msvm_VirtualSystemSettingDataComponent" `
    -ComputerName $HyperVParent | Where-Object { $_.ResourceSubType -match "Microsoft Physical Disk Drive" }

ForEach-Object -InputObject $PhysicalDiskResource -Process {
    Write-Host "Passthrough Disk At: " ([WMI]$_.HostResource[0]).ElementName
    Write-Host "Passthrough Disk Drive Number: " ([WMI]$_.HostResource[0]).DriveNumber
}

Taylor Brown
Hyper-V Integration Test Lead
http://blogs.msdn.com/taylorb

New Hyper-V WMI Doc’s… Plus It’s Official I’ll Be Speaking at PDC… Plus Cluster Fix for Hyper-V…

taylorb — Sat, 09 Aug 2008 03:25:28 GMT

Hyper-V WMI Documentation

First off I am happy to say the Hyper-V WMI documentation is finally post beta quality! I want to personally thank a few members of the test team for writing much of the sample code and working very hard to get it posted. There are now samples in C# and VBScript for most of the common methods (sadly now Powershell so my crusade/purpose continues)…

Storage(Msvm_ImageManagementService):
http://msdn.microsoft.com/en-us/library/cc136845(VS.85).aspx

Networking(Msvm_VirtualSystemManagementService):
http://msdn.microsoft.com/en-us/library/cc136938(VS.85).aspx

VMMS(Msvm_VirtualSwitchManagementService):
http://msdn.microsoft.com/en-us/library/cc136940(VS.85).aspx

Hyper-V WMI Documentation

Secondly…It’s official I will be babbling on about Hyper-V and Test Automation at PDC – pretty excited it should be fun. Here’s a link to the Channel 9 page. http://channel9.msdn.com/pdc2008/ES09/

Cluster Fix for Hyper-V

Thirdly… The Cluster team has released a hotfix to add “Increased functionality and virtual machine control” to the cluster manager. Here’s a link to the page http://support.microsoft.com/?id=951308

Taylor Brown
Hyper-V Integration Test Lead
http://blogs.msdn.com/taylorb

PDC 2008 Here We Come!

taylorb — Fri, 01 Aug 2008 19:00:00 GMT

Hyper-V will be well represented at the Microsoft Professional Developers Conference (PDC) this year. Additional sessions where posted today (http://www.microsoftpdc.com/Agenda/Sessions.aspx) and they include two Hyper-V sessions. The first is Developing Solutions For Hyper-V Using WMI and the second is Enabling Test Automation Using Hyper-V. I am especially excited as I am currently slated to be giving the Enabling Test Automation session. PDC always has great sessions but this years are looking especially great, Windows 7, Live Mesh, Home Server, Cloud, Silverlight but still the best of all is Hyper-V ;-).

Taylor Brown
Hyper-V Integration Test Lead
http://blogs.msdn.com/taylorb

Hyper-V WMI: Creating a Thumbnail Image

taylorb — Tue, 29 Jul 2008 16:00:00 GMT

Hyper-V has a WMI API that will allow you to create a thumbnail image of any running or paused virtual machine. You can create any sized thumbnail you want (640x480, 800x600, 1024x768 etc…). Creating the image is pretty easy, you just call GetVirtualSystemThumbnailImage passing a reference to an Msvm_VirutalSystemSettingData instance and the size of the image you want… However getting something useful from the returned data is a bit tricky… You get an array of unit8’s that represent pixels, the API doesn’t have much choice and luckily Powershell makes this not an impossible feat. All you have to do is create a new bitmap object and read (marshal) the pixel data into the object… So here’s a script for you!


Running Virtual Machine	Saved Virtual Machine

Powershell Script:

[System.Reflection.Assembly]::LoadWithPartialName("System.Drawing")

$HyperVParent = "localhost"
$HyperVGuest = "Windows Server 2008 - x64"
$ImagePath = "c:\Temp"
$xRes = 640
$yRes = 480

$VMManagementService = Get-WmiObject -class "Msvm_VirtualSystemManagementService" -namespace "root\virtualization" -ComputerName $HyperVParent
$Vm = Get-WmiObject -Namespace "root\virtualization" -ComputerName $HyperVParent -Query "Select * From Msvm_ComputerSystem Where ElementName='$HyperVGuest'"
$VMSettingData = Get-WmiObject -Namespace "root\virtualization" -Query "Associators of {$Vm} Where ResultClass=Msvm_VirtualSystemSettingData AssocClass=Msvm_SettingsDefineState" -ComputerName $HyperVParent
$RawImageData = $VMManagementService.GetVirtualSystemThumbnailImage($VMSettingData, "$xRes", "$yRes") #| ProcessWMIJob $VMManagementService.PSBase.ClassPath "GetVirtualSystemThumbnailImage"

$VMThumbnail = new-object System.Drawing.Bitmap($xRes, $yRes, [System.Drawing.Imaging.PixelFormat]::Format16bppRgb565)

$rectangle = new-object System.Drawing.Rectangle(0,0,$xRes,$yRes)
[System.Drawing.Imaging.BitmapData] $VMThumbnailBitmapData = $VMThumbnail.LockBits($rectangle, [System.Drawing.Imaging.ImageLockMode]::WriteOnly, [System.Drawing.Imaging.PixelFormat]::Format16bppRgb565)
[System.Runtime.InteropServices.marshal]::Copy($RawImageData.ImageData, 0, $VMThumbnailBitmapData.Scan0, $xRes*$yRes*2)
$VMThumbnail.UnlockBits($VMThumbnailBitmapData);

$VMThumbnail
$VMThumbnail.Save("$ImagePath\$HyperVGuest.jpg")

Taylor Brown
Hyper-V Integration Test Lead
http://blogs.msdn.com/taylorb

Hyper-V WMI: KVP Exchange aka Data Exchange (Retrieving and Modifying Parent/Host KVP’s)

taylorb — Thu, 10 Jul 2008 03:00:00 GMT

On Sunday I showed how to add registry keys to the guest from the host (Hyper-V WMI: KVP Exchange aka Data Exchange (Adding New Items From Parent/Host)) and on Monday I showed how to read registry key’s written by the guest from the host (Hyper-V WMI- KVP Exchange aka Data Exchange (Adding New Items From Guest)). Today I am going to show how to retrieve previously added host keys and modify there values…

Retrieving Previously Added Key’s

filter Import-CimXml
{
    $CimXml = [Xml]$_
    $CimObj = New-Object -TypeName System.Object
    foreach ($CimProperty in $CimXml.SelectNodes("/INSTANCE/PROPERTY"))
    {
        $CimObj | Add-Member -MemberType NoteProperty -Name $CimProperty.NAME -Value $CimProperty.VALUE
    }
    $CimObj
}

$Vm = Get-WmiObject -Namespace root\virtualization -Query "Select * From Msvm_ComputerSystem Where ElementName='vista'"
$Kvp = Get-WmiObject -Namespace root\virtualization -Query "Associators of {$Vm} Where AssocClass=Msvm_SystemDevice ResultClass=Msvm_KvpExchangeComponent"
$GuestKvp = Get-WmiObject -Namespace root\virtualization -Query "Associators of {$Kvp} Where AssocClass=Msvm_ElementSettingData ResultClass=Msvm_KvpExchangeComponentSettingData"
$GuestKvp.HostExchangeItems | Import-CimXml

Modifying Previously Added Key’s

This is almost identical to the script to add a KVP except in this case you need to provide a Name of an existing KVP and call the ModifyKvpItems method…
Note: If you are using my ProcessWMIObject function and getting a blank error message you should update to the latest version posted 7/6.

$ComputerName = "localhost"

$VMManagementService = Get-WmiObject -class "Msvm_VirtualSystemManagementService" -namespace "root\virtualization" -ComputerName $ComputerName
$Vm = Get-WmiObject -Namespace root\virtualization -ComputerName $ComputerName -Query "Select * From Msvm_ComputerSystem Where ElementName='Vista'"
$Kvp = Get-WmiObject -Namespace root\virtualization -ComputerName $ComputerName -Query "Associators of {$Vm} Where AssocClass=Msvm_SystemDevice ResultClass=Msvm_KvpExchangeComponent"

$Msvm_KvpExchangeDataItemPath = "\\$ComputerName\root\virtualization:Msvm_KvpExchangeDataItem"
$Msvm_KvpExchangeDateItem = ([WmiClass]$Msvm_KvpExchangeDataItemPath).CreateInstance()
$Msvm_KvpExchangeDateItem.Name = <Previous Key Name>
$Msvm_KvpExchangeDateItem.Data = "Foo"
$Msvm_KvpExchangeDateItem.Source = 0

$VMManagementService.ModifyKvpItems($Vm, $Msvm_KvpExchangeDateItem.PSBase.GetText(1))

Taylor Brown
Hyper-V Integration Test Lead
http://blogs.msdn.com/taylorb

Hyper-V WMI: KVP Exchange aka Data Exchange (Adding New Items From Guest)

taylorb — Tue, 08 Jul 2008 03:00:00 GMT

Yesterday’s post (Hyper-V WMI: KVP Exchange aka Data Exchange (Adding New Items From Parent/Host)) showed how to add registry key’s into the guest so that the guest could receive information from the host. Today’s post will show how to add a registry key in the guest so that the host can retrieve it…

Step 1 – Add a registry key to the guest…

Use your faviorite registy editing tool such a reg.exe or powershell.

Examples:
Reg.exe: reg add "HKLM\SOFTWARE\Microsoft\Virtual Machine\Guest" /v test /t REG_SZ /d testing
Powershell: New-ItemProperty -path "HKLM:\SOFTWARE\Microsoft\Virtual Machine\Guest" -name test2 -value testing

Step 2 – Query the value from the host…

This might look very similar to Hyper-V WMI Using PowerShell Scripts – Part 3 (KVP's - Guest OS Version) it is…(just the last line changes :-))

Output:

Caption     :
Data        : testing
Description :
ElementName :
Name        : test
Source      : 1

Caption     :
Data        : testing
Description :
ElementName :
Name        : test2
Source      : 1

Taylor Brown
Hyper-V Integration Test Lead
http://blogs.msdn.com/taylorb

Hyper-V WMI: KVP Exchange aka Data Exchange (Adding New Items From Parent/Host)

taylorb — Mon, 07 Jul 2008 01:35:08 GMT

I have gotten a ton of questions about the KVP Exchange or Data Exchange Integration Component… So what is it and how do I use it? The KVP Integration component allows the guest and host to query and provide information to each via pairs of Key’s and Value’s. The KVP integration component provides some basic Key’s and Value’s for you, I talked about the host accessible ones in a previous post Hyper-V WMI Using PowerShell Scripts – Part 3 (KVP's - Guest OS Version) these include things like the fully qualified name, OS version, Processor Architecture etc… There are also some guest accessible values that provide some information on the parent (host) such as HostName, PhysicalHostName, PhysicalHostNameFullyQualified, and VirtualMachineName. These values are located in registry under “HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Virtual Machine\Guest\Parameters”. The other thing you can do via the KVP is write registry key’s from the parent (host) and read guest provided registry key’s from the parent (host). Today I am going to show how to write key’s from the parent into the guest.

Add-KVP.ps1 Script

The AddKvpItems method returns a WMI Job Object see Hyper-V WMI- Rich Error Messages for Non-Zero ReturnValue (no more 32773, 32768, 32700…) for very helpful method to provide rich error messages.

$ComputerName = "localhost"

$VMManagementService = Get-WmiObject -class "Msvm_VirtualSystemManagementService" -namespace "root\virtualization" -ComputerName $ComputerName
$Vm = Get-WmiObject -Namespace root\virtualization -ComputerName $ComputerName -Query "Select * From Msvm_ComputerSystem Where ElementName='Vista'"
$Kvp = Get-WmiObject -Namespace root\virtualization -ComputerName $ComputerName -Query "Associators of {$Vm} Where AssocClass=Msvm_SystemDevice ResultClass=Msvm_KvpExchangeComponent"

$Msvm_KvpExchangeDataItemPath = "\\$ComputerName\root\virtualization:Msvm_KvpExchangeDataItem"
$Msvm_KvpExchangeDateItem = ([WmiClass]$Msvm_KvpExchangeDataItemPath).CreateInstance()
$Msvm_KvpExchangeDateItem.Name = "Test4"
$Msvm_KvpExchangeDateItem.Data = "Testing"
$Msvm_KvpExchangeDateItem.Source = 0

$VMManagementService.AddKvpItems($Vm, $Msvm_KvpExchangeDateItem.PSBase.GetText(1))

And as you can see I have a new registry entry… (btw 64bit Vista SHWEEET!)

Taylor Brown
Hyper-V Integration Test Lead
http://blogs.msdn.com/taylorb

Hyper-V WMI: Rich Error Messages for Non-Zero ReturnValue (no more 32773, 32768, 32700…)

taylorb — Thu, 19 Jun 2008 07:29:00 GMT

Since I did my last post on snapshots I have gotten several comments and few e-mails asking how to map ReturnValues to actual human readable strings. I guess not every one just knows that 32773 is Invalid Parameter… Well after many hours of asking and playing I have the answer – or at least a good start so here it is:

The real magic is this in ProcessWMIJob… it now operates on the pipeline and can take two new parameters one for the WmiClassPath and a second for the MethodName… It uses those to retrieve the error strings for the specific class and function from WMI… To use this just put it at the top of your scripts or in your environment and party on…

filter ProcessWMIJob
{
    param
    (
        [string]$WmiClassPath = $null,
        [string]$MethodName = $null
    )

    $errorCode = 0

    if ($_.ReturnValue -eq 4096)
    {
        $Job = [WMI]$_.Job

        while ($Job.JobState -eq 4)
        {
            Write-Progress $Job.Caption "% Complete" -PercentComplete $Job.PercentComplete
            Start-Sleep -seconds 1
            $Job.PSBase.Get()
        }
        if ($Job.JobState -ne 7)
        {
            if ($Job.ErrorDescription -ne "")
            {
                Write-Error $Job.ErrorDescription
                Throw $Job.ErrorDescription
            }
            else
            {
                $errorCode = $Job.ErrorCode
            }
        }
        Write-Progress $Job.Caption "Completed" -Completed $TRUE
    }
    elseif($_.ReturnValue -ne 0)
    {
        $errorCode = $_.ReturnValue
    }

    if ($errorCode -ne 0)
    {
        Write-Error "Hyper-V WMI Job Failed!"
        if ($WmiClassPath -and $MethodName)
        {
            $psWmiClass = [WmiClass]$WmiClassPath
            $psWmiClass.PSBase.Options.UseAmendedQualifiers = $TRUE
            $MethodQualifiers = $psWmiClass.PSBase.Methods[$MethodName].Qualifiers
            $indexOfError = [System.Array]::IndexOf($MethodQualifiers["ValueMap"].Value, [string]$errorCode)
            if ($indexOfError -ne "-1")
            {
                Throw "ReturnCode: ", $errorCode, " ErrorMessage: '", $MethodQualifiers["Values"].Value[$indexOfError], "' - when calling $MethodName"
            }
            else
            {
                Throw "ReturnCode: ", $errorCode, " ErrorMessage: 'MessageNotFound' - when calling $MethodName"
            }
        }
        else
        {
            Throw "ReturnCode: ", $errorCode, "When calling $MethodName - for rich error messages provide classpath and method name."
        }
    }
    return $_
}

Example:

$VHDService = get-wmiobject -class "Msvm_ImageManagementService" -namespace "root\virtualization"
$VHDService.CreateDynamicVirtualHardDisk("C:\Users\Public\Documents\Hyper-V\Virtual hard disks\MyVHD.vhd", 20GB) | ProcessWMIJob $VHDService "CreateDynamicVirtualHardDisk"

Revised 7/6 To Add Support For WMI Jobs that have blank Error Descriptions.
Revised 7/28 To Return Created Object on Success and To Add Sample Code...

Taylor Brown
Hyper-V Integration Test Lead
http://blogs.msdn.com/taylorb

Hyper-V WMI: Creating/Applying/Deleting Virtual Machine Snapshots

taylorb — Tue, 17 Jun 2008 05:35:00 GMT

After I finished writting this I relized it got a bit long... - I guess I had a lot to talk about! Hope you enjoy it (or at least find it mildly useful)

Hyper-V implements a feature known as snapshots, this should not be confused with a SAN snapshot or a VSS snapshot these snapshots are quite different. A Hyper-V snapshot allows you to save off the current state of a virtual machine even while the virtual machine is running or paused. You can then you can revert back to this state at a latter point… You can create tree’s of snapshots (see screen shot), think about application testing when you might need an XP RTM image, XP SP1, XP SP2, XP SP1 that was upgraded to SP2 and then rolled back to SP1 etc… With a snapshot tree you can create all of these interesting combinations without having to reinstall a physical or virtual machine 20 times… and when the next service pack comes out you can just apply the interesting base snapshots create a new snapshot and install the service pack – Major Time Saver!

The way a snapshot works is that Hyper-V creates a copy of the virtual machine configuration (network connections, disk configuration, cpu count, ram count etc…) Hyper-V then creates a special diffrencing VHD file known as an AVHD for every virtual hard disk connected to the VM to prevent the current VHD from being changed. If the virtual machine is running a full copy of the guest memory is also saved – unlike a saved state the virtual machine continues to run while this is occurring. There are a few things that should be noted, since Hyper-V effectively uses a diffrencing VHD to branch the hard disk state VM’s that are using passthough disks or cd’s can not be snapshoted. Along the same lines just like diffrencing VHD files have a disk read and write performance penalty over a fixed or even dynamically expanding VHD snapshots to incur this cost. Another thing to note is that the AVHD file and saved memory file by default is located in the same location as the virtual machine configuration, this can be changed either by creating the virtual machine in a non-default location or more comely in the Virtual Machine Settings’s UI under Management (Snapshot File Location).

Snapshot’s are excellent for test and development they are a huge time saver. They are also great for staging up a server you get the ability to undo when you accidentally type the wrong machine name or password… Just remember to merge your snapshots before putting the server into production, to merge a snapshot you just deleted the snapshot tree with the virtual machine off, it will then start a background merge which you can monitor from the Hyper-V management UI. When the merge is completed you will have a flat VHD that you can then put into production with no-performance impact. Now let’s see some code!

Taking a Snapshot

Applying a Snapshot

$VMManagementService = Get-WmiObject -Namespace root\virtualization -Class Msvm_VirtualSystemManagementService
$SourceVm = Get-WmiObject -Namespace root\virtualization -Query "Select * From Msvm_ComputerSystem Where ElementName='VmToSnapshot'"
$Snapshot = Get-WmiObject -Namespace root\virtualization -Query "Associators Of {$SourceVm} Where AssocClass=Msvm_ElementSettingData ResultClass=Msvm_VirtualSystemSettingData"

$result = $VMManagementService.ApplyVirtualSystemSnapshot($SourceVm, $Snapshot)
#ProcessWMIJob($result)

Deleting a Snapshot

$VMManagementService = Get-WmiObject -Namespace root\virtualization -Class Msvm_VirtualSystemManagementService
$SourceVm = Get-WmiObject -Namespace root\virtualization -Query "Select * From Msvm_ComputerSystem Where ElementName='VmToSnapshot'"
$Snapshot = Get-WmiObject -Namespace root\virtualization -Query "Associators Of {$SourceVm} Where AssocClass=Msvm_ElementSettingData ResultClass=Msvm_VirtualSystemSettingData"

$result = $VMManagementService.RemoveVirtualSystemSnapshot($Snapshot)
#ProcessWMIJob($result)

Enumerating Snapshots

$SourceVm = Get-WmiObject -Namespace root\virtualization -Query "Select * From Msvm_ComputerSystem Where ElementName='VmToSnapshot'"
Get-WmiObject -Namespace root\virtualization -Query "Associators Of {$SourceVm} Where AssocClass=Msvm_ElementSettingData ResultClass=Msvm_VirtualSystemSettingData" | Format-List -Property ElementName, InstanceID

Enumerating Snapshots – With a bit more information…

$SourceVm = Get-WmiObject -Namespace root\virtualization -Query "Select * From Msvm_ComputerSystem Where ElementName='VmToSnapshot'"
$Snapshots = Get-WmiObject -Namespace root\virtualization -Query "Associators Of {$SourceVm} Where AssocClass=Msvm_ElementSettingData ResultClass=Msvm_VirtualSystemSettingData"

$script:list = @()
foreach ($Snapshot in $Snapshots)
{
    $SnapObj = New-Object -TypeName System.Object
    $SnapObj | Add-Member -MemberType NoteProperty -Name SnapshotName -Value $Snapshot.ElementName
    $SnapObj | Add-Member -MemberType NoteProperty -Name SnapshotID -Value $Snapshot.InstanceID
    $SnapObj | Add-Member -MemberType NoteProperty -Name SnapshotParentName -Value ([WMI]$Snapshot.Parent).ElementName
    $script:list += $SnapObj
}
$script:list

ProcessWMIJob Function

Put this block at the top of your script and uncomment the ProcessWMIJob call if you want the function call to wait for completion and provide error messages…

function ProcessWMIJob
{
    param
    (
        [System.Management.ManagementBaseObject]$Result
    )

    if ($Result.ReturnValue -eq 4096)
    {
        $Job = [WMI]$Result.Job

        while ($Job.JobState -eq 4)
        {
            Write-Progress $Job.Caption "% Complete" -PercentComplete $Job.PercentComplete
            Start-Sleep -seconds 1
            $Job.PSBase.Get()
        }
        if ($Job.JobState -ne 7)
        {
            Write-Error $Job.ErrorDescription
            Throw $Job.ErrorDescription
        }
        Write-Progress $Job.Caption "Completed" -Completed $TRUE
    }
    elseif ($Result.ReturnValue -ne 0)
    {
        Write-Error "Hyper-V WMI Job Failed!"
        Throw $Result.ReturnValue
    }
}

ENJOY!

Taylor Brown
Hyper-V Integration Test Lead
http://blogs.msdn.com/taylorb

Hyper-V WMI – Configuring Automatic Startup/Shutdown/Recovery Action’s For Virtual Machines

taylorb — Sun, 15 Jun 2008 02:18:48 GMT

Hyper-V virtual machines have configuration options that control what happens when the parent/host server shuts down, start’s up, or if a virtual machine’s worker process terminates unexpectedly. The first two conditions (parent/host shutdown, startup) are pretty self explanatory but what would cause a worker process to terminate? There are a couple reasons, one would be if someone terminates the process, another would be if the process detects an security attack coming from the virtual machine, others reasons could be if there was bad hardware or a programming error (i.e bug) in either Hyper-V or another component in the system…

The default Automatic Startup Action is to start the virtual machine if it was running when the server was shutdown. Another option is to always startup the virtual machine irrespective of the state of the virtual machine when the server was shutdown. The last option is none – this translates to leave the virtual machine off or saved when the server starts up.

The default Automatic Shutdown Action is to save any running virtual machines. There are two other options, first is to turn off any running virtual machines and second is to shutdown any running virtual machines using the shutdown integration component. The shutdown is forced – so any open/running programs will be terminated. If the shutdown request fails the vm will be turned off – this can happen for many reasons primarily because the IC’s aren’t installed or if the guest is in safe mode/booting up.

The default Automatic Recovery Action is to restart the virtual machine, the other options are to revert to the last snapshot if one exists or none – which again equates to leaving the virtual machine off.

There is one additional option that I wanted to discuss briefly is Automatic Startup Action Delay, this is the amount of time to wait after the server reboot before taking the automatic startup action. The default is zero – meaning take the action immediately. This option could be very helpful for some servers – if you have lower and higher priority virtual machines you might want to delay the startup of your low priority virtual machines.

So here’s some code:

$VirtualSystemManagemntService = get-wmiobject -class "Msvm_VirtualSystemManagementService" -namespace "root\virtualization"

foreach ($Vm in Get-WmiObject -Namespace root\virtualization -Query "Select * from Msvm_ComputerSystem Where Description='Microsoft Virtual Machine'")
{
   $SettingData = Get-WmiObject -Namespace root\virtualization -Query "Associators of {$Vm} Where ResultClass=Msvm_VirtualSystemGlobalSettingData AssocClass=Msvm_ElementSettingData"
   $SettingData.AutomaticStartupAction = 0 #None=0, Restart if Previously Running=1, Always Startup=2
   $SettingData.AutomaticShutdownAction = 0 #Turn Off=0, Save State=1, ShutDown=2
   $SettingData.AutomaticRecoveryAction = 0 #None=0, Restart=1, Revert to Snapshot=2
   $SettingData.AutomaticStartupActionDelay = [System.Management.ManagementDateTimeconverter]::ToDmtfTimeInterval((New-TimeSpan -Minutes 10))

   $VirtualSystemManagemntService.ModifyVirtualSystem($Vm, $SettingData.PSBase.GetText(1))
}

ENJOY!

Taylor Brown
Hyper-V Integration Test Lead
http://blogs.msdn.com/taylorb

Hyper-V WMI – Cloning Virtual Machines Using Import/Export

taylorb — Sat, 07 Jun 2008 17:09:00 GMT

I have officially given up on the “Hyper-V WMI Using PowerShell Scripts” serious, not because of lack of interest but because or extreme interest implying that I would need to do Part 5, 6, 7, 99… Counting past 5 is hard so from now on I will just title the posts for what they are doing. Today’s post is going to be an end-to-end script to create 10 clones of a given VM.

Here’s a quick tour of the script…

This script takes 4 parameters:
     MasterVM – this is the name of the VM that will be cloned
     Path – this is the base path where the clones will reside
     NewName – this is what the cloned VM’s will be named
     HyperVHost – this is the name of the host that the script will execute against

The function ProcessWMIJob takes the return of a WMI method call and then processes the job waiting for the job to complete and throwing an exception if the job failed.

The main part of the script retrieves the Msvm_VirtualSystemManagmentService class and the MasterVM’s Msvm_ComputerSystem. It then loops 10 times, first changing the name of the VM and then exporting the VM and finally re-importing the VM. After it completes the 10 interactions it restores the name of original name of the MasterVM.

param
(
    [string]$MasterVM = $(Throw "MasterVM required"),
    [string]$Path = $(Throw "Path required"),
    [string]$NewName = "VMCopy",
    [string]$HyperVHost = "localhost"
)

function ProcessWMIJob
{
    param
    (
        [System.Management.ManagementBaseObject]$Result
    )

    if ($Result.ReturnValue -eq 4096)
    {
        $Job = [WMI]$Result.Job

        while ($Job.JobState -eq 4)
        {
            Write-Progress -Id 2 -ParentId 1 $Job.Caption -Status "Executing" -PercentComplete $Job.PercentComplete
            Start-Sleep 1
            $Job.PSBase.Get()
        }
        if ($Job.JobState -ne 7)
        {
            Write-Error $Job.ErrorDescription
            Throw $Job.ErrorDescription
        }
    }
    elseif ($Result.ReturnValue -ne 0)
    {
        Throw $Result.ReturnValue
    }
    Write-Progress $Job.Caption -Status "Completed" -PercentComplete 100 -Id 2 -ParentId 1
}

#Main Script Body
$VMManagementService = Get-WmiObject -Namespace root\virtualization -Class Msvm_VirtualSystemManagementService -ComputerName $HyperVHost
$SourceVm = Get-WmiObject -Namespace root\virtualization -Query "Select * From Msvm_ComputerSystem Where ElementName='$MasterVM'" -ComputerName $HyperVHost
$a = 0

while ($a -lt 10) {
    write-progress -Id 1 "Cloning Vm's" -Status "Executing" -percentcomplete (($a / 10)*100)
    $tempVMName = "$NewName - $a"
    $VMSettingData = Get-WmiObject -Namespace root\virtualization -Query "Associators of {$SourceVm} Where ResultClass=Msvm_VirtualSystemSettingData AssocClass=Msvm_SettingsDefineState" -ComputerName $HyperVHost
    $VMSettingData.ElementName = $tempVMName

    $Result = $VMManagementService.ModifyVirtualSystem($SourceVm, $VMSettingData.PSBase.GetText(1))
    ProcessWMIJob $Result

    $Result = $VMManagementService.ExportVirtualSystem($SourceVm, $TRUE, "$Path")
    ProcessWMIJob $Result

    $Result = $VMManagementService.ImportVirtualSystem("$Path\$tempVMName", $TRUE)
    ProcessWMIJob $Result

    $a ++
}

write-progress -Id 1 -Completed $TRUE -Activity "Cloning Vm's"
$VMSettingData = Get-WmiObject -Namespace root\virtualization -Query "Associators of {$SourceVm} Where ResultClass=Msvm_VirtualSystemSettingData AssocClass=Msvm_SettingsDefineState" -ComputerName $HyperVHost
$VMSettingData.ElementName = $MasterVM

$Result = $VMManagementService.ModifyVirtualSystem($SourceVm, $VMSettingData.PSBase.GetText(1))
ProcessWMIJob $Result

- Taylor Brown
- Hyper-V Test Team