VM backups failing when using NBD vs Hotadd

[pouya]

Hi All, just trying have a quick sanity check re the backup transport modes. I wanted to ask some questions before I reach out to Support as that will most likely take a long time get resolved or get marked as 'network issue'.

I just wanted to understand if there was any fundamental difference in data transfer for Hot add vs NBD?

Currently, we are facing an issue that all of our jobs that use NBD are failing sporadically with -

Processing <vmname> Error: Failed to connect to the port [veeamrepo:2523].

So clearly the error is port related within the data mover range. However we also have hotadd based backups using the same proxies/repositories that work without a hitch.

Is there a fundamental difference in how that data transfer occurs that might help me address the issue on our side before opening a case? Our network team already said overall they dont see any major faults but perhaps if I knew a bit better where to check it might help.

Thank you!

[Mildur]

Hi Philipp

I just wanted to understand if there was any fundamental difference in data transfer for Hot add vs NBD?

NDB:
1) Backup Proxy reads data of the source VM disks from the management Port of the ESXI Host
2) Sends the compressed/encrypted data to the Backup Repository

Hot Add:
1) Backup Proxy mounts the source VM disks from a vSphere datastore
2) Backup Proxy reads the data from the mounted VM disk
3) Sends the compressed/deduplicated/encrypted data to the Backup Repository

The used port to send backups from the proxy to the repository is between 2500-3500 (Default range, can be adjusted by the backup admin).
We will start with 2500 and open new ports as required if multiple VM or agent backups are running simultaneously.
Please check that you have open those ports on your Firewall.

I recommend to open a support case and let them analyze your issue:
Processing <vmname> Error: Failed to connect to the port [veeamrepo:2523].
Please don't forget to provide me with the case number.

Best,
Fabian