I wanted to create a function that could help an IT Pro Admin with the task to create a clone of a running VM, Yes you can use the Export-VM cmdlet but then your VM must be turned off and in some cases, for example when you want to test a new release or patch on a production system but first test it in a safe environment and you are not allowed to stop the original VM.

The function exists in System Center Virtual Machine Manager but there it also must be turned off

So how do I do? I have made a PowerShell function that take a snapshot, copies the vhd files and creates a new VM, connect the vhd´s and network cards, configures the VM with number of processors, dynamic memory etc.

As the Snapshot merges the vhdx files when the VM is running in this new Hyper-V version I thought it was an sufficient way to solve that the VM actually was not writing to the .vhdx files when I copy them but into the .avhdx diff file.

This is a version 0.1 and yes it need some development but right now I do not have the time to make it supernice,

Here you can see it in action

And when It is finished It looks like this in the gui

And here is the PowerShell function

<#
.Synopsis
   Function to clone a running VM
.DESCRIPTION
   This function can be used to clone a running vm and connect the copied vhd´s and network
.EXAMPLE
   Clone-VM -VMName vmdisktest -VMCloneName vmdisktest-clone -Path c:\VMs
.EXAMPLE
   Clone-VM -VMName vmdisktest -VMCloneName vmdisktest-clone -Path c:\VMs -Switch Private
.Notes
Author: Niklas Akerlund
Date: 2012-06-19
#>
function Clone-VM
{
    [CmdletBinding()]
    [OutputType([int])]
    Param
    (
        # Name of the VM to be cloned
        [Parameter(Mandatory=$true,
                   ValueFromPipelineByPropertyName=$true,
                   Position=0)]
        $VMName,
        [string] $VMCloneName,
        # Where to store the VM-clone 
        [string] $Path,
        # Set to another network switch
        [string] $Switch = " "    
    )

    # Get VM
    $VM = Get-VM $VMName
    $VHDs = Get-VMHardDiskDrive -VM $VM
    #$VHDPath = (Get-VMHardDiskDrive -VM $VM).Path
    $VHDClonePath = "$Path\$VMCloneName\Virtual Hard Disks\"
    
    # Create a new array of VHD info
    $VHDOrg = @()
    foreach ($VHD in $VHDs){
        $data = New-Object PSObject -property @{
            VHDName = (Get-Item $VHD.Path).Name
            VHDPath = $VHD.Path
            ControllerType = $VHD.ControllerType
            ControllerNumber = $VHD.ControllerNumber
            ControllerLocation = $VHD.ControllerLocation

        }
        $VHDOrg +=$data
    }

    $VMNics = Get-VMNetworkAdapter -VM $VM

    # Take snapshot 
    $VM | Checkpoint-VM 

    New-Item -ItemType directory -Path $VHDClonePath

    New-VM -Name $VMCloneName -Path $Path -NoVHD -MemoryStartupBytes $VM.MemoryStartup -BootDevice IDE
    $VMClone = Get-VM -Name $VMCloneName
    Get-VMNetworkAdapter -VMName $VMCloneName | Remove-VMNetworkAdapter
   
    # Configure VM-Clon
    if ($VM.DynamicMemoryEnabled){
        Set-VM -VMName $VMCloneName -ProcessorCount $VM.ProcessorCount -DynamicMemory -MemoryMinimumBytes $VM.MemoryMinimum -MemoryMaximumBytes $VM.MemoryMaximum
    }else{
        Set-VM -VMName $VMCloneName -ProcessorCount $VM.ProcessorCount -StaticMemory
    }

    # Add all network cards
    foreach ($VMNic in $VMNics){
        if ($Switch -eq " "){
            Add-VMNetworkAdapter -VMName $VMCloneName -SwitchName $VMNic.SwitchName -IsLegacy $VMNic.IsLegacy
        }else{
            Add-VMNetworkAdapter -VMName $VMCloneName -SwitchName $Switch -IsLegacy $VMNic.IsLegacy
        }
    }

    # Copy all VHDs
    foreach ($VHDcopy in $VHDOrg){
        
        $Dest = $VHDClonePath + $VHDcopy.VHDName
        Copy-Item -Path $VHDcopy.VHDPath -Destination $Dest
        Add-VMHardDiskDrive -VMName $VMCloneName -ControllerType $VHDCopy.ControllerType -ControllerLocation $VHDCopy.ControllerLocation  -ControllerNumber $VHDCopy.ControllerNumber -Path $Dest   
    }

    # Remove snapshot 
    $VM | Remove-VMSnapshot

}

Good luck in testing, but do take in consideration that this is an copy of the running VM so do not start it at the same time on the same network or you will get IP collision etc, as you can see above I have added an -Switch parameter that you can use to set the network cards of the VM to be connected on another switch to avoid any problems.. 🙂

A colleague wanted a script for a reconfiguration of a VM´s settings. Once the VM is powered off that is not a big issue. The smart thing is when using Powershell version 3 I can configure a scheduled job that I want to execute off hours.

Imagine that you have the task to add a vCPU to a VM but you can only do it during the service window that happens to be around midnight, I don´t know about you but I rather sleep then if I can automate it. Yes I could in earlier versions use scheduled task but now I am using Win 2012 and Hyper-V 3 and the latest powershell.

So what do I need to do then, Jan Egil Ring has made a blog post about scheduled jobs and I want to show an example regarding Virtual Machine management..

In Powershell version 3 there are 16 cmdlets regarding scheduled jobs

First I need a Trigger

$once = New-JobTrigger -Once -At 11:59PM

Then I need a job with the trigger, I could use a parameter -FilePath to use a script file instead of -ScriptBlock

Register-ScheduledJob -ScriptBlock {$vm = Get-VM TestVM2 ; Stop-VM -VM $vm ; Set-VM -VM $vm -ProcessorCount 2 ; Start-VM -VM $vm} -Trigger $once

And then just wait or sleep 😛

And here you can see a screendump of the changing, Now I changed the trigger time to not have to wait to midnight for the blog post but I think you can imagine…

To check that the Job went ok, you run the cmdlet Get-Job ( and if you do not get any job you might need to run import-module PSScheduledJob to get the right Get-Job in that session)

God luck in scheduling your VM tasks 🙂

In the PowerCLI world there is a kind of evil oneliner to remove all VM´s from a datacenter, I was searching for something alike in the Hyper-V v3 world

The PowerCLI command is

Get-VM | %{Stop-VM $_ -Confirm:$false; Remove-VM $_ -DeletePermanently -Confirm:$false

And of course that is pure evil because the parameter -deletepermanently will remove not only the VM but also it´s files from the datastore, The % is to take care of each VM and in case the VM is running I will shut it down (otherwise if I only run like Get-VM | Stop-VM -Confirm:$false | Remove-VM -deletePermanently -Confirm:$false I will only remove the ones running, cause I will get an error on the others because I cannot change state to what it is already)

In Hyper-V and the powershell v3 It is not quite as easy but of course it can be done and don´t you dare use the gui 😉

This approach requires that you have put your VM in a separate folder for each of them (or of course it will be clean in your default Hyper-V VM folder..)

The Remove-VM cmdlet does not allow you to actually remove the VM´s virtual hard disk and the folders (which in some times can become a bit messy after a while)

Here is my VM´s

And here is my folder

So if I remove one VM now with the Remove-VM TestVM1, this also requires that the VM is off.

And lets see in the folders what do we have

So to clean both VM´s and folder data I run all at once and this looks like this

Get-VM testvm* | %{ Stop-VM -VM $_ -Force; Remove-VM -vm $_ -Force ; Remove-Item -Path $_.Path -Recurse -Force}

And see in my VM´s folder how tidy and neat it is 😛

And as I started to describe in the top .. If you just use Get-VM | …  you will clean your Hyper-V host quick 🙂

Now that the Windows 2012 RC has arrived with the Powershell v3 I wanted to explore the functionality a bit more, I have seen some posts about how to use the Workflows but none when deploying VM´s in Hyper-V.

I have loaned some code from Mikael Nyström (Deployment Bunny) but had to rewrite a little to make it work with the workflow -parallel.

Also when I downloaded Mikael´s scripts they where automatically  blocked ( I had set my demo system to -Unrestricted) but as you see in the screenshot they are still blocked. but luckily I can use the Unblock-File cmdlet in the Powershell v3, when using the v2 there was a utility tool streams.exe from SysInternals that could help.

and here is it in the properties dialog

But if I have like 5-10 or 100 files I would like to use Powershell (Anyone out there unblocking like 100 scriptfiles by clicking in a dialog?)

To create the “Master” vhdx I used the Convert-WindowsImage.ps1 script, I am creating the master to be deployed with win 2012 RC datacenter core version (Updated:I got a tip in the comments to look at the Convert-WindowsImage instead of the Wim2VHD.ps1)

Now to my workflow, I am testing to create 5 VM´s at the same time with differential disks connected to the master. the workflows also set all VM´s to dynamic memory and starts them.

# Inparallel.ps1
#
# Niklas Akerlund
# 2012-06-03

workflow create-VMs
{
    $VMRefDisk = "C:\VMs\master.vhdx"
    $VMNetwork = "Intern"
    $VMBaseLocation = "C:\VMs"
    $VMMemory = 384MB
    foreach -parallel ($item in 1..5) {
          
        $VMName = "TestVM$item"    
        $VMLocation = New-Item -Path "$VMBaseLocation\$VMName" -ItemType Directory -Force
        $VMDiskLocation = New-Item -Path "$VMLocation\Virtual Hard Disks" -ItemType Directory -Force
        $VMDisk01 = New-VHD –Path $VMDiskLocation\$VMName-OSDisk.vhdx -Differencing –ParentPath $VMRefDisk 
  
        New-VM –Name $VMname –MemoryStartupBytes $VMMemory –VHDPath $VMDisk01.path -SwitchName $VMNetwork -Path $VMBaseLocation
   
        Set-VM -VMName $VMName -DynamicMemory

        Start-VM -VMName $VMName
    }
    Get-VM TestVM*
}

It is quite simple but still powerfull, If I for example had like more hosts i can deploy many VM´s at the same time and the thing that would stop me is the hardware and the storage 😛

I read this post by Ben (Virtual PC Guy) Armstrong about shrinking a virtual hard disk and thought this should be done with powershell.

So first I have to shrink the partition inside the VM, for this I use the New-CIMSession (instead of powershell remoting and such) and then I shut down the VM and shrink the VHDx file, As someone correctly noted, this shrink of the virtual disk file is only possible when using the new VHDx format.

The VM is part of the same domain as the hyper-V server from which I am running the script, this made it easier to make a cim connection. The VM is also a Win 8 beta cause I need the latest win framework with powershell 3.

As you can see, the disk in my VM is 60 GB and I want to shrink it to the minimum size * 20% (so i get at least some space left 😉

Now I will run my little script and here is what that looks like

# vNiklas Masterblaster shrink
#
# Niklas Akerlund / 2012-05-13

$VM = "Shrink8"

$cim = New-CimSession $VM

$partitionC = Get-Partition -CimSession $cim -DriveLetter C

$newSize = ($partitionC | Get-PartitionSupportedSize).SizeMin*1.20

Resize-Partition -PartitionNumber $partitionC.PartitionNumber -DiskNumber $partitionC.DiskNumber -Size $newSize -CimSession $cim

Get-Volume C -CimSession $cim

$VM = Get-VM $VM

Stop-VM $VM

$hdd = $VM | Get-VMHardDiskDrive

Resize-VHD -Path $hdd.Path -ToMinimumSize

Start-VM $VM

And here you can see the result, a quite simple solution..

Good luck in your shrinking 🙂

Update:  I totally missed that Ben had done a post about doing it with powershell, just after his other post when i was making this post… At least my solution show how to connect to a VM with CIM 🙂