Param($Arg1)
$targetvhd = $Arg1
if (($targetvhd -eq $null) -or !(Test-Path $targetvhd)) {
  Write-Host "Error: targetvhd missing"
  exit
}
dir $targetvhd
Mount-VHD $targetvhd -NoDriveLetter -Readonly
Optimize-VHD $targetvhd -Mode Quick
Optimize-VHD $targetvhd -Mode Quick
Dismount-VHD $targetvhd
dir $targetvhd