If by RJ45 you mean erhernet over standard 8P8C (i.e. RJ45) your looking for SFP-T modules. Can’t connect that to your DSL line though since that’s not Ethernet.

There do seem to exist G.fast sfp modules for dsl, but do note that sadly sfp module and router brand incompatibility is sadly a thing.

Related note: At our company we also had quite some issues getting some of these more special sfp modules working (e.g. XGS-PON), so ymmv with a dsl one.

(If you’re looking for a device to plug sfp modules into, I can second MikroTik here. They’re also great about accepting 3rd party SFPs)

If your dsl is G.Fast you could try the Zyxel GM4100. That device is only a bridge

No I’m talking about VMs. It’s the baloon kernel driver which also works on Windows (though needs separate installation). It doesn’t work quite like containers though. The hypervisor dynamically adds/removes memory to the VM depending on total memory usage of the hypervisor.

See https://pve02.northcode.ch:8006/pve-docs/chapter-qm.html#qm_memory

Nowadays you can also assign a dynamic amount of memory. I’ve only ever used this with Linux VMs on Proxmox though, but I’m pretty sure it works with Windows as well