Cannot find dirty block information in the previous restore point, CBT will not be used

[mashiro2004]

Hi,
i have a vm with 10 virtual disk with about 55TB of data to transfer via replication every 2 hours.
I run the full replica, then when i run incremental i see the: Cannot find dirty block information in the previous restore point, CBT will not be used and job re-read the entire 55TB of vm for a total of 20 hours.
I run another incremental and everything ok, then after 2 hours replication start again and again CBT problem, i don't know if is my problem and how i can solve this, becasue is important for me to have a DR site replicated every 2 hours and not every 20 hours, i open a support tk: 07254866

Many thanks
Simone

[david.domask]

Hi Simone,

Thank you for sharing the case number; it looks like it's a recently opened case, so let's allow Veeam Support some time to review the provided logs. Just out of curiosity, this only happens on the Replica job, the normal Backup Job does not have this issue or you also see that the backups are not using CBT?

[mashiro2004]

Hi,
Dirty Block appear not as error or warning but like a information.
For this vm for now i make replication only and not backup with veeam (backup for now is managed by software vendor).
This vm is business critical is a vm that contain images x-rays, CT scans etc of an hospital. Previuos this vm was replicated by storage replication, but now we want to migrate all storage replication to veeam replication.

Many thanks
Simone

[david.domask]

Hi Simone,

Thank you for the details -- I would ask that you please include that in the case if you have not already, and details on the software doing the backup may be relevant as it's possible that is affecting the CBT for the VM. A manual reset of CBT may be necessary, but let's allow the Support Team to review the situation first before you make changes.

[mashiro2004]

Hi it is an rsync not a backup with 3rd party software.

[david.domask]

Got it, then let's wait for the Support Team to report back on their findings. I can see some activity on the case, so please continue with the Support Team within the case.

[pierardy]

Hi,
May be late but I receive this warning CBT when snapshot (vmware) is present on this VM.

Check if yours conditions

[mashiro2004]

the problem seems to be due to the fact that the disks are very large and veeam is unable to calculate the digests in the pre-established time and goes into timeout, the technical support made me increase the value of the digest calculation time and for 3 days I have no longer had errors. Let's wait a little longer before closing the case.

[mashiro2004]

NO problem not solved....
Support ask me to disable storage snapshot