Proxmox

Proxmox VE is the hypervisor most homelab and club setups reach for when a laptop stops being enough. It is not the only option, but it is the one this page explains, because it is the one the lab is most likely to run on.

1. A Bare-Metal Hypervisor

A hypervisor is software that lets one physical machine run several virtual machines at once. Proxmox is a type-1, or bare-metal, hypervisor. It installs directly onto the server’s hardware. There is no underlying Windows, macOS, or Linux desktop underneath it — Proxmox is the operating system on that box.

This is different from running VirtualBox on your laptop. VirtualBox is a type-2 hypervisor. It installs as an app on top of an OS you already use for everything else — browsing, email, homework. Every VM you run competes with your own desktop for CPU, memory, and disk.

Proxmox skips that layer. The whole machine exists to run VMs, and nothing else runs on it competing for resources. That is why one Proxmox server can comfortably host many VMs at once, where a laptop running VirtualBox struggles past two or three.

2. VMs vs. LXC Containers

Proxmox can create two different kinds of guest: a full VM or an LXC container.

A VM emulates an entire computer. It gets its own virtual CPU, its own memory, its own virtual disk, and it boots its own kernel — the core program that talks to hardware. This is true even though the hardware is virtual. A VM does not know, or care, that it is not real.

An LXC container is lighter. It shares the host server’s kernel instead of booting its own. It still looks like a separate Linux machine from the inside — its own filesystem, its own processes, its own IP address — but it starts in a second or two instead of a minute, and uses a fraction of the memory.

Use a VM when you need a different operating system than the host, such as Windows, or when you need strong isolation because you are running something risky. Use an LXC container when you just need a lightweight Linux service — a DNS server, a small web app — and speed matters more than isolation.

3. Storage and Snapshots

Every VM and container needs a disk. Proxmox calls the place that disk lives storage — it can be a local drive on the server, or something more advanced like a networked storage pool. For a club lab, local storage on the server is enough to start.

The feature that matters most for a lab is the snapshot. A snapshot freezes a VM’s exact state — disk contents, and often memory — at one moment in time. Restoring a snapshot rewinds the VM back to that moment, undoing everything that happened after.

This matters because a lab is a place you are supposed to break things. You will misconfigure a service, run an exploit that corrupts a database, or delete a file you needed. Without a snapshot, that mistake costs you a full reinstall. With one, it costs you thirty seconds and a click.

Snapshots do not usually copy the whole disk again each time. Proxmox tracks only the changes made after the snapshot, and discards those changes on restore. That is why taking one is fast, even on a large VM.

4. Virtual Networks — Keeping the Lab Off Campus

Proxmox connects VMs to the network through a virtual bridge — a software switch that behaves like a physical network switch, except it lives entirely inside the hypervisor. A VM’s virtual network card plugs into a bridge the same way a real computer’s cable plugs into a real switch.

This matters more than any other setting on the box. A lab exists so members can attack things safely — and “safely” means the traffic never reaches the FAU campus network. A virtual bridge with no path out to the campus network is what makes that true. Build the lab’s VMs on an isolated bridge, and an exploit, a scan, or a mistake inside the lab has nowhere to go but the lab.

Do not treat this as optional configuration to get to later. It is the one setting that turns “a lab” into “a machine that can reach FAU’s network,” which is a very different, and not allowed, thing. If you are setting up a lab VM and you are not sure which bridge it is on, stop and check before you do anything else on it.

5. Templates and Cloning

Building a VM by hand — install the OS, apply updates, install tools — is slow, and doing it the same way twice by memory is unreliable. Proxmox solves this with templates.

A template is a VM you have already built and configured once, then marked as read-only. From a template, you clone new VMs in seconds instead of minutes. Each clone starts as an exact copy of the template’s disk.

For a lab, this is what makes rebuilding practical. Build one clean Windows template and one clean Linux template. When a member breaks their VM badly enough that a snapshot cannot fix it, clone a fresh one from the template instead of reinstalling from scratch.

6. Why One Shared Box

A club could ask every member to install a hypervisor on their own laptop instead. Some members already do, for personal practice — see Virtual Machines for that path. But a shared club lab is a different goal, and it needs a shared box.

A laptop hypervisor is limited by that one laptop’s CPU, memory, and disk. A range with a domain controller, several clients, and a server (see Building an End-to-End Range) is heavier than most laptops can run well, especially alongside the owner’s normal schoolwork.

A shared server also means everyone works from the same environment. A misconfigured VM on one member’s laptop is that member’s problem alone. The same VM on a shared, snapshotted, template-backed server is something the next member can reset and reuse. That reusability is the entire point of a club lab over a personal one.