Disk Hard disk # has incorrect changed block tracking configuration

By Arne Fokkema - ICT-Freak.nl

Today another Veeam troubleshooting trick. It’s possible that you’ll receive the following error in one of your Veeam Backup Jobs:

Verifying change block tracking:
Disk “Hard disk 1” has incorrect changed block tracking configuration

This is how it looks in the Veeam Backup console:

The procedure which Veeam describes in the solution for this problem works like this:

1. Shutdown the VM
2. VM – Edit Settings – Options – General – Configuration Parameters…
3. Change every item with ctkEnabled to false
4. Start the VM
5. Start the Backup Job to see if this is the solution for this problem.

This is how you change the parameter to false:

In my case, the above solution did not solve the problem. So I had to troubleshoot the VM. While checking the configuration I noticed that the Disk was configured with the Independent mode enabled. You can change this setting when the VM is powered off. Go to Hardware, select the Hard disk and disable the checkbox by Independent:

The setting above can only be changed when the VM is powered off, if you’re using the vSphere client. It’s also possible to change this setting, on-the-fly with PowerCLI. That rhymes .

You can run the following one-liner to disable the Independent mode:

Get-VM <vmName> | % { Get-HardDisk -VM $_ | Where {$_.Persistence -eq "IndependentPersistent"} | `
% {Set-HardDisk -HardDisk $_ -Persistence "Persistent" -Confirm:$false} }

Disclaimer: this one-liner worked for me in my environment but test this first because I don’t know exactly what the impact is of this change.