§ What is changed data block?
Changed data block refers to the disk data blocks that change from the last backup snapshot to the current backup snapshot.
§ How to ensure successful incremental backup?
1) The job is already backed up successfully and the point in time retained from the last successful backup is not deleted; 2) After the VM is backed up successfully, the retained snapshot is not deleted, and the VM disk is not expanded and no new disk is added.
§ For how to start an incremental backup, see Starting a Backup Job.