Share CBT data between backup jobs?

[mikegoodwin]

Hi,

Does Veeam share CBT data between backup jobs? Or would it be different for each backup job?

We had a VMserver crash, and so all CBT data is invalid.

Some of the VM's on the server are backed up / replicated in a number of different jobs, and the first time each job ran it had to re-read the entire VMDK. I expected this for the first job, but I thought it wouldn't be needed for any further jobs?

As I am typing, part of me thinks that the CBT data would be per job, as it is tracking changes between job runs, and is correct only for a particular "point in time".

Just thought I'd ask, as I am not sure

Thanks,
Mike

[Vitaliy S.]

Hi Mike,

CBT data is stored per job, cause these jobs can have different schedule, VMs etc.

Thanks!

[dellock6]

CBT infos are not stored by Veeam, but they are in the vSphere environment, specifically in the same folder of the vmx configuration file, in a dedicated file. Veeam read those info during an incremental run.
If CBT for any reason has to be reset, no matter what's the history of the VM in previous job runs, the first job hitting the VM after a CBT reset has to read again the virtual disk as there's no CBT information anymore.
CBT is like a change log for vmdk blocks, and it's read by any job accessing the same VM. There's no issue in having multiple jobs accessing the same VMs.