Hi,When proxmox makes a backup, it takes more resources and the website on VM goes down of resource lack.
I have proxmox on the host and backups are going to proxmox backup server.
qm config <VMID> and your
cat /proc/pressure/cpu and
cat /proc/pressure/memory after the VM backup was running.
journalctl -b -r gives you a paginated view of the journal in reverse order.
fio and perform a
proxmox-backup-client benchmark --repository <string> giving your repository as target. See also https://pbs.proxmox.com/docs/backup-client.html#benchmarking