I found this great Powershell script that convert virtual disk files to eagered zeroed.

Awesome script! I had to make some changes to make it work in my environment.

 function Set-EagerZeroThick{
 param($vcName, $vmName, $hdName)

# Find ESX host for VM
 $vmImpl = Get-VM $vmName
 Write-Host $vmImpl
 if($vmImpl.PowerState -ne "PoweredOff"){
 Write-Host "Guest must be powered off to use this script !" -ForegroundColor red
 return $false
 }

 $vm = $vmImpl | Get-View
 Write-Host $vm
 $esxName = (Get-View $vm.Runtime.Host).Name
 Write-Host $esxName
# Find datastore path
 $dev = $vm.Config.Hardware.Device[10] | where {$_.DeviceInfo.Label -eq $hdName}
 Write-Host $dev
 if($dev.Backing.thinProvisioned){
 return $false
 }
 $hdPath = $dev.Backing.FileName
 Write-Host $hdPath

# For Virtual Disk Manager we need to connect to the ESX server
 $esxHost = Connect-VIServer -Server $esxName -User $esxAccount -Password $esxPasswd

# Convert HD
 $vDiskMgr = Get-View -Id (Get-View ServiceInstance -Server $esxHost).Content.VirtualDiskManager
 Write-Host $vDiskMgr
 $dc = Get-Datacenter -Server $esxHost | Get-View
 Write-Host $dc
 $taskMoRef = $vDiskMgr.EagerZeroVirtualDisk_Task($hdPath, $dc.MoRef)
 Write-Host $taskMoRef
 $task = Get-View $taskMoRef
 Write-Host $task
 while("running","queued" -contains $task.Info.State){
 $task.UpdateViewData("Info")
 }

 Disconnect-VIServer -Server $esxHost -Confirm:$false

# Connect to the vCenter
 Connect-VIServer -Server $vcName
 if($task.Info.State -eq "success"){
 return $true
 }
 else{
 return $false
 }
}

$vmName = "vm1"
$vCenter = "vcenter_server"
$esxAccount = "rootuser"
$esxPasswd = "password"

Set-EagerZeroThick $vCenter $vmName "Hard disk 1"

To validate before and after running the eageredZeroed script I run the following script:

$vm = Get-VM vm1 | Get-View
$vm.config.Hardware.Device[10].backing
$vm.config.Hardware.Device[10].DeviceInfo

Source: http://www.lucd.info/2009/11/15/scripts-for-yellow-bricks-advise-thin-provisioning-alarm-eagerzeroedthick/

A couple of days ago I found a really great PowerCLI script that move templates i vSphere. Awesome post and script by afokkema at ict-freak.nl!

Storage vMotion is a great feature to Move your VMs to other datastores. But what if you want to move your Templates?
In the current version of vSphere there is no option within the Client

function Move-Template{
    param( [string] $template, [string] $esx, [string] $datastore)

    if($template -eq ""){Write-Host "Enter a Template name"}
    if($esx -eq ""){Write-Host "Enter an ESX hostname"}
    if($esx -ne "" -and $datastore -eq ""){$vmotion = $true}
    if($datastore -ne ""){$svmotion = $true}

    Write-Host "Converting $template to VM"
    $vm = Set-Template -Template (Get-Template $template) -ToVM 

    if($svmotion){
        Write-Host "Migrate $template to $esx and $datastore"
        Move-VM -VM (Get-VM $vm) -Destination (Get-VMHost $esx) `
        -Datastore (Get-Datastore $datastore) -Confirm:$false
        (Get-VM $vm | Get-View).MarkAsTemplate() | Out-Null
    }        

    if($vmotion){
        Write-Host "Migrate $template to $esx"
        Move-VM -VM $vm -Destination (Get-VMHost $esx) -Confirm:$false
        ($vm | Get-View).MarkAsTemplate() | Out-Null
    }
}

The function above can be used to move a single template via:

Move-Template <template> <esxhost> <datastore>

Source: http://ict-freak.nl/2010/01/21/powercli-move-template/