NovaBackup Datacenter 5.4 added support for VMware 6.0 for Virtual Machine backup.
However, VMware ESXi 6.0 Update 1a, released 10/06/2015, contains a major bug which affects backup software which utilizes the native Change Block Tracking (CBT) feature, like NovaStor. The resolve for that is to install the latest build of VMware ESXi which was released on 11/25/2015. The one newer build than that for VMware 6 has been released on 11/25/2015, which specifically fixes the “backup software using CBT” bug, and these are the release notes.
After installing the latest version of VMware ESXi then you can re-try the backup job. Both the 10/06/2015 build and the 11/25/2015 builds were listed as “Critical bug fix” patches for VMware ESXi 6.0. Here is the list of VMware ESXi versions/builds to read all of the version release notes.
Summaries and Symptoms:
This patch resolves an issue that occurs when you run virtual machine backups which utilize Changed Block Tracking (CBT) in ESXi 6.0, the CBT API call QueryDiskChangedAreas() might return incorrect changed sectors that results in inconsistent incremental virtual machine backups. The issue occurs as the CBT fails to track changed blocks on the VMs having I/O during snapshot consolidation.