Power-V: PowerShell scripts for managing Hyper-V virtual machines

Power-V.psm1

function Get-OrphanedVHDs {
	$rootedVHDs = (Get-VM).HardDrives.Path + (Get-VM | Get-VMSnapshot).HardDrives.Path
	Return Get-ChildItem (Get-VMHost).VirtualHardDiskPath | Where-Object { $_.FullName -notin $rootedVHDs }
}

function New-VirtualMachine {
Param(
	$Name,
	$MemoryBytes,
	$VHDSizeBytes,
	$IsoPath,
	$SecureBootTemplate,
	$SwitchName
)

	# If a switch name hasn't been provided, it'll try to find a default.
	if (!$SwitchName) {
		$Switches = Get-VMSwitch | Where-Object SwitchType -eq 'External'
	
		#If there's only one switch with external connectivity, that's it.
		#Else, a switch name should have been provided.
		if ($Switches.Count -eq 1) {
			$SwitchName = $Switches.Name
		}
	}

	$VHDPath = Join-Path -Path (Get-VMHost).VirtualHardDiskPath -ChildPath ($Name + ".vhdx")
	if ($SecureBootTemplate -eq "MicrosoftWindows") {
		$null = New-VHD -Path $VHDPath -SizeBytes $VHDSizeBytes 
	}
	else {
		$null = New-VHD -Path $VHDPath -SizeBytes $VHDSizeBytes -BlockSizeBytes 1MB
	}
	$VM = New-VM -Name $Name -MemoryStartupBytes $MemoryBytes -Generation 2 -BootDevice VHD -SwitchName $SwitchName -VHDPath $VHDPath
	Set-VM $VM -ProcessorCount 2 -MemoryMaximumBytes $MemoryBytes -AutomaticCheckpointsEnabled $false
	Add-VMDvdDrive $VM -Path $IsoPath
	Set-VMFirmware $VM -BootOrder ((Get-VMFirmware $VM).BootOrder | ? BootType -eq 'Drive') 
	if ($SecureBootTemplate) {
		Set-VMFirmware $VM -SecureBootTemplate $SecureBootTemplate
	}
	else {
		Set-VMFirmware $VM -EnableSecureBoot Off
	}
	Return $VM
}

function Remove-VirtualMachine {
Param(
	$VMName
)

	$vm = Get-VM $VMName
	$snapshot = (Get-VMSnapshot $vm | ? ParentSnapshotName -eq $null)
	if ($snapshot) {
		$vhds = $snapshot.HardDrives.Path
	}
	else {
		$vhds = $vm.HardDrives.Path
	}
	Remove-VM $vm -Force
	Remove-Item $vhds
}