ESXi Host Did Not Provide Valid CBT Data

Product version: 9.0

Last modified: 27 August 2019


An error message states that the source VMware ESXi host did not provide valid CBT data.


After the initial (full) VM backup or replication, all subsequent job runs are forever incremental. By default, NAKIVO Backup & Replication uses the VMware CBT technology to identify which data has changed since the last job run. Several factors – such as a power outage – can cause VMware CBT to reset and lose track of incremental changes for a VM. If an ESXi host is unable to provide correct CBT data for a VM, the above error message is displayed. 


By default, backup and replication jobs are configured to handle CBT errors automatically as follows:

  1. Re-try querying CBT several times; if unsuccessful:

  2. Attempt to reset CBT for this VM automatically.

  3. Perform initial (full) backup/replication for the VM.

  4. Start using VMware CBT again on the next job run.

You can change the behavior by editing the job and setting a different error handling on the Options page of VM backup jobs and VM replication jobs.

You can also reset CBT for the VM manually.