Fix-VMcbt.ps1

 # Fix the locked changed block tracking file for vms in a VMWare environment.
# It it achieved by flipping the changed block tracking settings.
# Snapshot is used as an alternative so the setting can be changed.
# Requires VMWare PowerCLI 5.1 and PowerShell V3 or above.

#Add the required PowerPLI cmdlets
Add-PSSnapin VMware.VimAutomation.Core

#Parameters
$vCenter="vCenter"
$vm="vm1","vm2","vm3"

#Connect to the vCenter server
Connect-VIServer $vCenter

foreach ($v in $vm){

    $vmfix = Get-vm $v | Get-View
    $vmConfigSpec = New-Object VMware.Vim.VirtualMachineConfigSpec
   
    #Reconfigure the vm to disable the changed block tracking.
    $vmConfigSpec.changeTrackingEnabled = $false
    $vmfix.reconfigVM($vmConfigSpec)

    $snapshot = New-Snapshot $v -Name "Disable changed block tracking"
    $snapshot | Remove-Snapshot -confirm:$false

    #Reconfigure the vm to  enable the changed block tracking back again.
    $vmConfigSpec.changeTrackingEnabled = $true
    $vmfix.reconfigVM($vmConfigSpec)
   
    $snapshot = New-Snapshot $v -Name "Enable changed block tracking"
    $snapshot | Remove-Snapshot -confirm:$false

}


Disconnect-VIServer $vCenter