@icompit Thank you. It seems that the backup process fails to get the file lock on the backup directory. Have you modified anything on your remote recently? Also, could you tell me if this is happening on all of this job's runs, all of your backup runs, or if it only happened once on this specific backup job execution?

@KPS Unfortunate, no. I just replicate and avoid moving live VM on the same host, target for replication.

I quickly discussed with Xen developers and they are curious about your issue. Can you do a lspci -vvvv in your Dom0, first while you have still the option pci=realloc, and once without it, and see if we can spot any difference regarding your NIC. This might be helpful (you can provide both outputs at https://paste.vates.tech)