Challenge
Leveraging VMware Changed Block Tracking (CBT) data supplied by VMware ESXi 6.0 can potentially render the data in backups or replicas inconsistent or corrupt.
Cause
This is a VMware ESXi issue in CBT logic that affects ESXi 6.0 through ESXi 6.0 Update 1a. It is resolved with VMware ESXi 6.0 patch ESXi600-201511001. Please see VMware KB article for additional information about the issue.
Solution
Installing the patch alone is not sufficient, CBT reset is also required for all of your VMs. CBT reset is mandatory in every scenario, because existing CBT maps may already be inconsistent due to the original bug, which in turn may result in inconsistent full backups in future.
Please follow this article to reset CBT. Please note that performing Active Full backups cannot be considered as a substitute to CBT reset with this particular CBT bug.