Check CBT status for all VMs:
Get-VM | select Name, @{N="CBT";E={(Get-View $_).Config.ChangeTrackingEnabled}}
To enable CBT
Write-Host "This script enables CBT for a VM"
$vm = read-host "Specify VM name"
Get-VM $vm | select Name, @{N="CBT";E={(Get-View $_).Config.ChangeTrackingEnabled}}
write-host "Proceed ?"
pause
$vmView = Get-vm $vm | get-view
$vmConfigSpec = New-Object VMware.Vim.VirtualMachineConfigSpec
$vmConfigSpec.changeTrackingEnabled = $true
$vmView.reconfigVM($vmConfigSpec)
Get-VM $vm | select Name, @{N="CBT";E={(Get-View $_).Config.ChangeTrackingEnabled}}
Write-host "Done.