For what it’s worth, I have a server with two rj45s (and a third for BMC), but I only plugged one of them into my switch. I run anywhere from 2-8 containers/vms on that server and never felt the need to hook up the other jack. I guess there’s probably some contention of running multiple hosts all through that one connection, but typically I don’t really need anything faster than the ~2-400mbps I get with WiFi anyway. So to answer you question, it depends, but I would generally say maybe start with the one and don’t worry about it unless you’re really moving massive amounts of data regularly and saturating your line. You’d also need to consider you’ll need a switch and other network hardware capable of handling that throughout as well if you’re really going to potentially saturate those ports.

Debian 12 - bookworm

I have always gravitated toward Debian until recently. I run LXCs on proxmox and apparently Debian needs nesting enabled or else it takes around 30s to login. I think it’s trying to access a system file when a user logs in that can’t be accessed when nesting is disabled, and it waits to timeout before continuing with the login. Also, I have noticed that when running htop on Debian, it reports the total number of cores on my server, rather than the number of cores I have assigned to the container. Ubuntu doesn’t have either of these problems - I can run it with nesting disabled (more secure) and still login without delay, and htop reports only the number of cores I have assigned to the container.

These are small issues, and there’s probably a way to address them, but I haven’t found any solutions yet. And when I just want to spin up a LXC quickly so I can work on an idea/pipeline/whatever, I’m finding myself going with the more frictionless option lately.

Edit to add: I run all of this headless, so I can’t comment on GUI differences or anything like that