Just a little heads up:
http://www.running-system.com/take-care ... p-cbt-bug/
Short synopsis: "There is an issue with Change Block Tracking (CBT) in Express Patch 6 for ESXi 6 (Build 3825889) that can affect your backup if your backup software relies on CBT."
Affected are Windows VMs on HW version 7 to 11 and with any VMware Tools version on both thin and thick provisioned disks while doing backups with quiesced snapshots.
Solutions so far:
- don't use quiesced, i.e. application-aware snapshots
- or downgrade to a older ESXi6 version