Unable to retrieve next block transmission command

[aj_potc]

This is related to Case #04725806.

I've started using Veeam to back up a Linux bare metal server (managed by VBR). Things haven't gone well. Veeam has been far more troublesome than any backup solution I've ever used. After struggling with issues on a number of fronts, I thought I had everything solved until I was hit with a new error:

"Unable to retrieve next block transmission command"

I've searched the forums and found occasional reports of this error. Most of them focus on some network-related issue, and some users are able to resolve it by updating drivers or applying other hypervisor-specific fixes. Others suggest that it might be some transient network problem.

My backups don't involve any virtualization, and are sent over the public Internet from a dedicated agent to a dedicated server holding the repository. There's also no hardware firewall involved -- only simple firewalld. Although both agent and repository are in professional datacenters with high quality networks, I suppose that a network interruption could be to blame. So I retried the backup, and the issue happened again. I retried a third time, sending more terabytes of traffic over the Internet, and it failed at yet a different point.

This is especially odd, because during my testing I've already done several full backups from the same agent to the same repository, so I know it's possible. But now that the agent is in production, I can't make a backup to save my life (naturally).

As of now, support hasn't suggested anything helpful. They've stated that they can't pinpoint the problem.

Does anyone have any ideas or suggestions for how I can troubleshoot this?

Do I just keep trying to run it over and over, hoping for a successful run?

Thank you very much.

[HannesK]

Hello,
in the case you assume that the Linux agent is working fine with WAN connections

The user guide says different... while for Veeam Agent for Windows (and most VBR components) the user guide says. https://helpcenter.veeam.com/docs/agent ... tml?ver=50

High latency and reasonably unstable WAN links are supported.

this is not mentioned for Veeam Agent for Linux: https://helpcenter.veeam.com/docs/agent ... tml?ver=50

If you have network disconnects from time to time, then I would say the behavior you see is expected.

Best regards,
Hannes

[aj_potc]

Hi Hannes,

Thanks for your reply.

No, I have to admit it wasn't at all clear that the lack of that phrase in one document meant that it doesn't apply to that particular component of Veeam. My assumption (which I think is logical) was that all of your backup agents would operate in a similar way with regard to their handling of network connections.

I don't think it's really an acceptable response these days to say "our product doesn't support backups of Linux agents over the Internet or WAN links." You have to imagine that your customers have widely distributed systems and want to back them up reliably to their own infrastructure (which may not be at the same location).

So, I suppose this means that you still have work to do to get the Linux offering more mature. My issues up to this point would also point in that direction.

I hope you'll take my problem report as a suggestion for improvement.

Thanks again.

[HannesK]

Hello,
your assumption totally makes sense. Agree.

And yes, we are investigating improvements.

Best regards,
Hannes