How to get disk changed areas from CBT(changed block tracker) in VMware

Start by identifying the Managed Object Reference-ID (MORef-ID) of the VM.

If the VM is being protected by Veeam Backup & Replication, navigate to the log directory on the Veeam Server (%programdata%\Veeam\Backup). Within that directory, find the folder that is named after the job that the VM is protected by. Within the job folder will be a log named Task.<vmname>.<Ref-ID>.log
 
If the Ref-ID starts with “vm-“ the job is connecting to the vCenter server.
If the Ref-ID is just a number, the job is connecting to a standalone host.
 

1. Now using an web browser navigate to: https://<vc/host ip>/mob/?moid=<Ref-ID>
    
   Example for VC: https://abp-vc.abp.lab/mob/?moid=vm-688
   Example for host: https://esxi1.abp.lab/mob/?moid=26
   
   
2. Create a snapshot for the virtual machine, and note that snapshot ref-id on the MOB page.
   
   
3. On the MOB page for the VM click "QueryChangedDiskAreas"
   
   
   
   
4. Insert the following parameters:
   
   snapshot reference id
   device key of a virtual disk
   start offset (the beginning of the required changed area)
   change id (use "*"(star symbol) to query all used space)
   
   
   
   
5. Click "Invoke Method" and then result will be shown at the bottom in the same window.
   
   The table contains changed disk areas start offsets and lengths.