Function Clone-VMFromSnapshot {
<#
.SYNOPSIS
  Clones a VM from a Specified Snapshot
  
.DESCRIPTION
  Clones a VM from a Specified Snapshot, 
  if no snapshot is specified then it will clone from the current snapshot
  
.NOTES
  Author: Ryan McLean
  Website: http://ninet.org
  
.PARAMETER srcName
  Mandatory - VM to clone
  
.PARAMETER dstName
  Mandatory - Name for the clone
  
.PARAMETER Snapshot
  Optional - Snapshot on VM to clone
 
.PARAMETER VMHost
  Optional - Host to register the clone on, 
  			 If not specified then the same 
			 host as the machine to be cloned is used

.PARAMETER Pool
  Optional - Resource Pool to place the clone in, 
  			 If not specified then the same resource 
			 pool as the machine to be cloned is used 
  
.PARAMETER Datastore
  Optional - Name of the Datastore to create the clone on, 
  			 If not specified then the same datastore as 
			 the machine to be cloned is used
  
.PARAMETER CustomSpec
  Optional - If specified then will run the named customisation on the clone.

.EXAMPLE
  PS> Clone-VMFromSnapshot -srcName "MyVM" -dstName "NewVM"
  
  Will clone the currentstate of "MyVM" to "NewVM"
  
.EXAMPLE
  PS> Clone-VMFromSnapshot -srcName "MyVM" -dstName "NewVM" -Snapshot "Snap1"
  
  Will clone the state of "MyVM" at snapshot Snap1 to "NewVM"

.EXAMPLE
  PS> Clone-VMFromSnapshot -srcName "MyVM" -dstName "NewVM" -Snapshot "Snap1" -VMHost "Host1" -Pool "Pool1"
  
  Will clone the state of "MyVM" at snapshot Snap1 to "NewVM" 
  registering "NewVM" on Host1 in "Pool1"
  
.EXAMPLE
  PS> Clone-VMFromSnapshot -srcName "MyVM" -dstName "NewVM" -Snapshot "Snap1" -DataStore "DS1"
  
  Will clone the state of "MyVM" at snapshot Snap1 to "NewVM" 
   and creating it in the Datastore DS1
  
.EXAMPLE
  PS> Clone-VMFromSnapshot -srcName "MyVM" -dstName "NewVM" -Snapshot "Snap1" -CustomSpec "WinServer"
  
  Will clone the state of "MyVM" at snapshot Snap1 to "NewVM" 
  applying the Customisation Specification "WinServer"
#>
	[CmdletBinding()]
	param (
		   [Parameter(Mandatory=$true)][String] $srcName,
		   [Parameter(Mandatory=$true)][String] $dstName,
		   [String] $Snapshot,
		   [String] $VMHost,
		   [String] $Pool,
		   [String] $DataStore,
		   [String] $CustomSpec
	)
	Process {
		$vm = Get-View -ViewType VirtualMachine -Property Name,Parent,Snapshot -Filter @{"Name"=$srcName}
		$cloneFolder = $vm.parent # Just use the same folder as the original VM for simplicity
		$cloneName = $dstName
		$cloneSpec = new-object Vmware.Vim.VirtualMachineCloneSpec
		$cloneSpec.Location = new-object Vmware.Vim.VirtualMachineRelocateSpec

		if ($VMHost) {
			$VMHost = Get-View -ViewType HostSystem -Property Name,Parent -Filter @{"Name"=$VMHost}
			$cloneSpec.Location.Host = $VMHost.MoRef
			$pfilter = @{"Name"=$Pool; "Owner"=$VMHost.Parent.Value}
		} else {
			$pfilter = @{"Name"=$Pool;}
		}
		
		if ($Pool) {
			$Pool = Get-View -ViewType Resource -Property Name -Filter $pfilter
			if (($Pool).count -gt 1) {
				Write-Host "Resource Pool is ambiguous, ignoring."
			} else {
				$cloneSpec.Location.Pool = $Pool.MoRef
			}
		}
		
		if ($Datastore) {
			$cloneSpec.Location.Datastore = (Get-View -ViewType Datastore -Property Name -Filter @{"Name"=$DataStore}).MoRef
		}
		
		if ($Snapshot) {
			$cloneSpec.Snapshot = (Get-Snapshot -Name $Snapshot -VM $vm.Name).ExtensionData.Snapshot
		} else {
			$cloneSpec.Snapshot = $vm.Snapshot.CurrentSnapshot
		}
		
		if($CustomSpec) {
			$cloneSpec.Customization = (Get-OSCustomizationSpec -Name $CustomSpec).ExtensionData.Spec
		}
		$vm.CloneVM_Task( $cloneFolder, $cloneName, $cloneSpec )
	}
}