Veeam Backup and Replication can sometimes give the following warning when backing up:
Cannot use CBT: Soap fault. Error caused by file
/vmfs/volumes/GUID/VM Name/VM Disk Name.vmdk Detail:
”, endpoint: ”
This error is safe to ignore the first time it occurs, a CBT error will not cause your backup to fail. Basically it’s saying that Veeam was unable to use VMware Change Block Tracking, which is used to speed up incremental backups by keeping a sort of change journal against the vmdk disk (The VMs virtual hard disk). Most likely this error is caused by the unavailability of a full backup or CBT being disabled.
To see if CBT is disabled, in the vSphere Client, power off the VM, right click the VM, Click Edit, Settings, Options, Advanced / General, Configuration Parameters and make sure the VMs configuration file (.vmx) contains:
ctkEnabled = “TRUE”