Veeam replication cannot use CBT

[chinchilla]

Hi All,

I have question as below.

- VM1 size 1TB data, Veeam version 11, vSphere 7.0U2

- PRD Veeam backup PRD VM1 to local repository keep 28 restore point with Full backup on every Sat around 9 hours and daily incremental backup around 30 mins

- DR Veeam daily replication PRD VM1 to DR ESXi with keep 14 restore point, initial full replicate VM1 around 40 hours

- PRD Veeam and DR Veeam did not have network communicate each other

Refer DR Veeam replication job, it should be initial full replicate and all should be incremental, but we check the DR replication adnormal as below:

- DR daily replication finished within one hour and Data read few GB and Transferred few GB, except after PRD Veeam Full backup job, DR replication around 40 hours, Data read 1TB but Transferred only few GB, and it must occured after PRD Veeam full backup job

Is it affected by PRD Veeam backup job with "Reset CBT on each Active Full backup automatically" and the replication job cannot check the CBT?

If yes, any solution fix this?

[Andreas Neufert]

If you reset CBT (manually/automatically/... do not matter), then for all jobs the reference is lost.
For Jobs that are not forced to do a Active Full (your replication job in that case), we perform a "Snap and Scan" run. Which means we would read 100% of the data and transfer only the changed data.
From there Incremental Processing based on CBT will work again.
There is no workaround other than do not reset CBT.
Resetting CBT is only needed if you resize VMs or register VMs again. Veeam will perform in those cases CBT reset automatically.