Just upgraded your VMWare vmhost from 3.5 to 4.0 or 4.1? Read on

Hi all,

If you have recently upgraded your VM Host to ESX4.0, 4.1 or 5.0 you might want to run this code (after installing the vmware powershell extensions, this is a powershell script after all):

function reportchangetracking{

$vm_name = Get-VM -location [cluster_name] | get-view

$vmConfigSpec = New-Object VMware.Vim.VirtualMachineConfigSpec

foreach ($objitem in $vm_name) {

#Write-host $objitem.name, $objitem.config.changetrackingenabled

if($objitem.config.changetrackingenabled -neq "True"){

$vmConfigSpec.changeTrackingEnabled = $true

$vmView.ReconfigVM($vmConfigSpec)

#punch it Chewy (reloads config spec. better than having to shut the machine down)

sleep 3

Get-VM $objitem.name | New-Snapshot -Name "Temp"

sleep 5

Get-VM $objitem.name | Get-Snapshot | Where {$_.Name -eq "Temp"} | Remove-Snapshot -Confirm:$false

}

}

}

In ESX3.5, VMTools never quiesced the base disk properly when taking snapshots. This meant that when Windows Server 2008 came along with VSS, the tools didn't use it, and 3.5 never added in the setting the code does above.

When you upgraded your host, it never added this setting at the VM level, so this task needs to be done manually. If you have a lot of machines, headaches ensue. After running the script, it might be an idea to update the tools installation on your server anyway.

Note that you do not have to run this if you created a machine on ESX4.0 or greater. Its been done for you.

Use this script at your own risk. It's no fault of mine if you break something.

Thanks for reading,

Trev