Minimalist distribution for virtualization?

Question

linux

There is a small machine (a simple quad-core Celeron, 2GiB DDR3), on which pfSense is currently running (FreeBSD in fact), this is my router.
I would like to put some kind of virtualization on the machine, where in one virtual machine there will be pfSense, and in the other a small LEDE (a company for pfSense in order to support Wi-Fi adapters). You will need to connect two virtual machines with a grid and forward a couple of USB devices to virtual machines (USB 3.0 is VERY desirable) and, possibly, PCIe network cards.
In this regard, a miniature Linux distribution with Xen / KVM and a pseudo-graphical interface for managing virtual machines would be ideal. In addition to running virtual machines and installing security updates (preferably automatic), nothing more is needed from him. Putting something like Ubuntu minimalCD seems like a huge overkill, I would like something an order of magnitude smaller. Ideally, something like NixOS in spirit (haven't tried it yet, but it seems not so small, declarative configuration attracts). An example for Docker is Rancher OS.

Answer 1

You either make such a dist yourself or still take it ready. At the same time, I do not understand the desire for minimalism for a virtualization system?
Take proxmox , install your pfSense there, the rest is really minimalistic linux containers in lxc or in docker. Take some Alpine thread there and rejoice.
https://wiki.alpinelinux.org/wiki/Docker

Answer 2

ESXi free