I am Dale Hayter, a Microsoft and VMware certified Technical Consultant.

My blog has been built up over the years from my experience of working on an IT helpdesk and also from being out on-site.

Veeam / ESXi 6.0 – CBT Data is invalid, failing over to legacy incremental backup.

Over the last few days we have been migrating a customers virtual machines to several new vSphere ESXi 6.0 hosts. The virtual machines were vmotioned to the new hosts and not powered off unexpectendly. The next time the Veeam backups run all the VMs had the error message :

CBT data is invalid, failing over to legacy incremental backup. No action is required, next job run should start using CBT again. If CBT data remains invalid, follow KB1113 to perform CBT reset. Usual cause is power loss.


We tried resetting the Change block tracking for the VMs but they still errored. It appears this is a known issue with some builds of VMware ESXi 6.0. If you install a build equal or higher than 2715440 then all will be good 🙂

Source : VMware