Add disks to a VM

Why

Adding a disk to a VM is not a big issue. I can use Hyper-V console or Windows Admin Center or PowerShell. But because I need to do it on a frequent basis and it’s boring I wanted to find a better way.

Just a reminder – how to add VHD to a VM:

• In Hyper-V we use Settings menu for given VM:

  

  Select New, and then name it, select path and proper options.

• In Windows Admin Center we need to get to VMs menu, Inventory, select given VM and go to disks:

  

Then again, fill in proper path and options.

In PowerShell – it’s sligthly better:

There are two problems with this. First – I need to know WHERE to put the files for given VM. In general I have all disks on the same CSV – along with VM configuration. Second – it’s boring 🙂

The Idea

So, I wanted to speed this up a bit. What I know?

• In general I name disks according to this template: <VMName>_disk<number>.vhdx.
• Disks are in the same location as other VM files (like configuration).
• When disk is attached in correct order – it usually gets the same disk number within the Windows OS. This simplifies a bit later on.
• I use Hyper-V hosts from 2012R2 version to 2019.
• Some Hyper-V hosts are in different domains – meaning I need to use Credential parameter.
• Sometimes VHD is in a different location.
• Sometimes I want to manually name the VHD.
• I use dynamic disks now, but I want to support other types later on as well.

Knowing this I ended up with a function that will:

1. Use Invoke-Command
   1. I will be able to connect to different versions of Hyper-V
   2. I will be able to use optional Credential parameter to connect to Hyper-V hosts in different domains. Or run it from unprivilged powershell session.
   3. This will also work from PowerShell Core
2. Gather some basic info about disks of given VM.
   1. This will give me current VM path location
   2. And also the number of current VHDs. (remember the <VMName>_disk<number>.vhdx part?
3. Create VHD and then attach it to a VM.

Here’s the code:

	function Add-AHVMDisk {
	<#
	.SYNOPSIS
	Adds a new vhdx to Hyper-V VM
	.DESCRIPTION
	Creates a new VHDX in VM's default disk location with given size (VHDSize). Attaches to a VM.
	.PARAMETER ComputerName
	ComputerName of a HyperV Computer where VM is.
	.PARAMETER VMName
	VMName to which attach a new VHDX
	.PARAMETER VHDSize
	Size of the VHDX file to create.
	.PARAMETER VHDType
	Type of VHDX file. Currently only Dynamic is supported
	.PARAMETER Credential
	Alternate credentials to use to connect to ComputerName
	.EXAMPLE
	Add-AHVMDisk -ComputerName OBJPLWHV1 -VMName OBJPLWCON0 -VHDSize 100GB -VHDType Dynamic -Credential (Get-Credential)
	#>
	[Diagnostics.CodeAnalysis.SuppressMessageAttribute('PSAvoidUsingPlainTextForPassword', '')]
	[CmdletBinding()]
	Param(
	[Parameter(Mandatory = $True,
	ValueFromPipelineByPropertyName = $True)]
	[string]
	$ComputerName,
	[Parameter(Mandatory = $True,
	ValueFromPipelineByPropertyName = $True)]
	[string]
	$VMName,
	[Parameter(Mandatory = $True,
	ValueFromPipelineByPropertyName = $True)]
	[uint64]
	$VHDSize,
	[Parameter(Mandatory = $True,
	ValueFromPipelineByPropertyName = $True)]
	[ValidateSet('Dynamic')]
	[string]
	$VHDType,
	[Parameter(Mandatory = $false,
	ValueFromPipelineByPropertyName = $True)]
	[string]
	$VHDName,
	[Parameter(Mandatory = $false,
	ValueFromPipelineByPropertyName = $True)]
	[System.Management.Automation.CredentialAttribute()]
	$Credential
	)
	Process {
	$invokeProps = @{
	ComputerName = $ComputerName
	}
	if ($PSBoundParameters.ContainsKey('Credential')) {
	Write-Verbose –Message "Credential {$($Credential.UserName)} will be used to connect to Computer {$ComputerName}"
	$invokeProps.Credential = $Credential
	}
	else {
	Write-Verbose –Message "Processing Computer {$ComputerName} with default credentials of user {$($env:USERNAME)}"
	}
	Write-Verbose –Message "Processing adding new VHDX Disk to VM {$VMName} on Computer {$ComputerName}"
	$vhdProps = @{
	Path = ''
	SizeBytes = $VHDSize
	ComputerName = $ComputerName
	}
	Write-Verbose –Message "Getting VM {$VMName} properties from Computer {$ComputerName} to set Path for new VHDX"
	$VMCurrentHDD = Invoke-command @invokeProps –ScriptBlock { Get-VMHardDiskDrive –VMName $USING:VMName }
	$VMBaseHDDPath = $VMCurrentHDD[0].Path
	$VMCurrentVHDCount = ($VMCurrentHDD | Measure-Object ).Count
	$VMParentPath = Split-Path $VMBaseHDDPath –Parent
	if ($PSBoundParameters.ContainsKey('VHDName')) {
	$VHDFileName = $VHDName
	}
	else {
	$VHDFileName = "{0}_disk{1}.vhdx" -f $VMName, $VMCurrentVHDCount
	}
	$VHDPath = Join-Path $VMParentPath –ChildPath $VHDFileName
	$vhdProps.Path = $VHDPath
	Write-Verbose –Message "Setting disk type to {$VHDType} for {$VMName} on Computer {$ComputerName}"
	if ($VHDType -eq 'Dynamic') {
	$vhdProps.Dynamic = $true
	}
	Write-Verbose –Message "Creating new VHDX in {$($vhdProps.Path)} for {$VMName} on Computer {$ComputerName}"
	Invoke-Command @invokeProps –ScriptBlock {
	$vhdProps = $USING:vhdProps
	New-VHD @vhdProps
	}
	Write-Verbose –Message "Attaching new VHD for {$VMName} on Computer {$ComputerName}"
	Invoke-Command @invokeProps –ScriptBlock {
	Add-VMHardDiskDrive –VMName $USING:VMName –Path $USING:VHDPath
	}
	Write-Verbose –Message "Attached new VHD for {$VMName} on Computer {$ComputerName}"
	}
	}

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Add-AHVMDisk.ps1
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What’s next? Well a VHD needs to be formatted right? Booring:) Glad I have this Format Drive. Remotely.

Final approach

Well if I combine both of these functions I can do it in one swing. For multiple disks at once!

	#optional
	#$Creds = Get-Credential #Credki do VM – moga byc domenowe lub lokalne
	$NewVMDiskProps = @{
	VMProps = @{
	ComputerName = 'HyperV'
	VMName = 'VMName1'
	}
	VHDProps = @(
	@{
	VHDSize = 100GB
	VHDType = 'Dynamic'
	NewFileSystemLabel = 'Data'
	FileSystem = 'NTFS'
	},
	@{
	VHDSize = 150GB
	VHDType = 'Dynamic'
	NewFileSystemLabel = 'Data1'
	FileSystem = 'NTFS'
	}
	)
	OSName = 'OSName1'
	}
	foreach ($disk in $NewVMDiskProps.VHDProps) {
	$addDiskProps = $NewVMDiskProps.VMProps
	$addDiskProps.VHDSize = $disk.VHDSize
	$addDiskProps.VHDType = $disk.VHDType
	if($creds) {
	$addDiskProps.Credential = $creds
	}
	Add-AHVMDisk @addDiskProps –Verbose
	$formatDriveProps = @{
	ComputerName = $NewVMDiskProps.OSName
	NewFileSystemLabel = $disk.NewFileSystemLabel
	FileSystem = $disk.FileSystem
	}
	if($creds) {
	$formatDriveProps.Credential = $creds
	}
	Format-RemoteDrive @formatDriveProps –Verbose
	}

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NewDiskFormatted.ps1
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Here’s the output:

	VERBOSE: Processing Computer {HyperV} with default credentials of user {mczerniawski_admin}
	VERBOSE: Processing adding new VHDX Disk to VM {VMName1} on Computer {HyperV}
	VERBOSE: Getting VM {VMName1} properties from Computer {HyperV} to set Path for new VHDX
	VERBOSE: Setting disk type to {Dynamic} for {VMName1} on Computer {HyperV}
	VERBOSE: Creating new VHDX in {C:\AdminTools\VMName1\Virtual Hard Disks\VMName1_disk1.vhdx} for {VMName1} on Computer {HyperV}
	Number :
	PSComputerName : HyperV
	RunspaceId : 7acbb7e4–efc4–4222–93c9–f75618873037
	ComputerName : HyperV
	Path : C:\AdminTools\VMName1\Virtual Hard Disks\VMName1_disk1.vhdx
	VhdFormat : VHDX
	VhdType : Dynamic
	FileSize : 4194304
	Size : 107374182400
	MinimumSize :
	LogicalSectorSize : 512
	PhysicalSectorSize : 4096
	BlockSize : 33554432
	ParentPath :
	DiskIdentifier : D5F483DA–A1C7–4A01–BDBE–CBBD989D2F43
	FragmentationPercentage : 0
	Alignment : 1
	Attached : False
	DiskNumber :
	VERBOSE: Attaching new VHD for {VMName1} on Computer {HyperV}
	VERBOSE: Attached new VHD for {VMName1} on Computer {HyperV}
	VERBOSE: Processing computer {OSName1}
	VERBOSE: Creating PSSession to computer {OSName1}
	VERBOSE: Checking if there are any not initialized disks on {OSName1}
	VERBOSE: Found #{1} raw disk on {OSName1}
	VERBOSE: Processing disks on {OSName1}
	PSComputerName : OSName1
	RunspaceId : 0323298f–534c–4be1–9580–e7fa74734c6e
	ObjectId : {1}\\OSName1\root/Microsoft/Windows/Storage/Providers_v2\WSP_Volume.ObjectId="{6e4dd0d4-9b56-11e8-a29a-806e6f6e6963}:VO:\\?\Volume{
	b9306c9a-a189-4c5f-a103-737d77963206}\"
	PassThroughClass :
	PassThroughIds :
	PassThroughNamespace :
	PassThroughServer :
	UniqueId : \\?\Volume{b9306c9a–a189–4c5f–a103–737d77963206}\
	AllocationUnitSize : 4096
	DedupMode : 4
	DriveLetter : E
	DriveType : 3
	FileSystem : NTFS
	FileSystemLabel : Data
	FileSystemType : 14
	HealthStatus : 0
	OperationalStatus : {2}
	Path : \\?\Volume{b9306c9a–a189–4c5f–a103–737d77963206}\
	Size : 107356352512
	SizeRemaining : 107240054784
	VERBOSE: Removing PSSession to Computer {OSName1}
	VERBOSE: Processing Computer {HyperV} with default credentials of user {mczerniawski_admin}
	VERBOSE: Processing adding new VHDX Disk to VM {VMName1} on Computer {HyperV}
	VERBOSE: Getting VM {VMName1} properties from Computer {HyperV} to set Path for new VHDX
	VERBOSE: Setting disk type to {Dynamic} for {VMName1} on Computer {HyperV}
	VERBOSE: Creating new VHDX in {C:\AdminTools\VMName1\Virtual Hard Disks\VMName1_disk2.vhdx} for {VMName1} on Computer {HyperV}
	Number :
	PSComputerName : HyperV
	RunspaceId : 92ff5a28–a7cb–4b0f–b003–0e38d1d82608
	ComputerName : HyperV
	Path : C:\AdminTools\VMName1\Virtual Hard Disks\VMName1_disk2.vhdx
	VhdFormat : VHDX
	VhdType : Dynamic
	FileSize : 4194304
	Size : 107374182400
	MinimumSize :
	LogicalSectorSize : 512
	PhysicalSectorSize : 4096
	BlockSize : 33554432
	ParentPath :
	DiskIdentifier : 74742985–C2B3–4B01–AB80–E4B81006A489
	FragmentationPercentage : 0
	Alignment : 1
	Attached : False
	DiskNumber :
	VERBOSE: Attaching new VHD for {VMName1} on Computer {HyperV}
	VERBOSE: Attached new VHD for {VMName1} on Computer {HyperV}
	VERBOSE: Processing computer {OSName1}
	VERBOSE: Creating PSSession to computer {OSName1}
	VERBOSE: Checking if there are any not initialized disks on {OSName1}
	VERBOSE: Found #{1} raw disk on {OSName1}
	VERBOSE: Processing disks on {OSName1}
	PSComputerName : OSName1
	RunspaceId : ea37cf42–30b4–40a9–b94d–9e8e2d6dcec3
	ObjectId : {1}\\OSName1\root/Microsoft/Windows/Storage/Providers_v2\WSP_Volume.ObjectId="{6e4dd0d4-9b56-11e8-a29a-806e6f6e6963}:VO:\\?\Volume{
	0c1fa464-eb8c-4328-98cb-bc09a31e3385}\"
	PassThroughClass :
	PassThroughIds :
	PassThroughNamespace :
	PassThroughServer :
	UniqueId : \\?\Volume{0c1fa464–eb8c–4328–98cb–bc09a31e3385}\
	AllocationUnitSize : 4096
	DedupMode : 4
	DriveLetter : F
	DriveType : 3
	FileSystem : NTFS
	FileSystemLabel : Data
	FileSystemType : 14
	HealthStatus : 0
	OperationalStatus : {2}
	Path : \\?\Volume{0c1fa464–eb8c–4328–98cb–bc09a31e3385}\
	Size : 107356352512
	SizeRemaining : 107240054784
	VERBOSE: Removing PSSession to Computer {OSName1}

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Transcript.ps1
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