Learn LXC - Pre-Requisites Skill & Environment Setup

#Introduction

Welcome to the Learn LXC series! This series will take you from mastering LXC (Linux Containers) — an OS-level virtualization technology that runs a complete Linux distribution (system container) on the same kernel as the host — through a total of 23 episodes in six phases, from namespaces & cgroups concepts to production readiness on homelab, edge, and Proxmox VE.

Before you touch lxc-create -n c1 -t download ..., there are basic skills and software you must have. Why does this prerequisite matter? Because LXC works at the kernel layer: it relies on namespaces for isolation and cgroups for resource limits. Without understanding these layers, you'll struggle to diagnose when a container has no network or when a memory limit isn't being enforced.

Episode 0 is your roadmap: we make sure the basic skills are covered, prepare the host, install the LXC 7.0 LTS tooling, and verify the environment for the first time.

#Basic Skills You Must Have

#Linux Admin and CLI

LXC is managed almost entirely through the terminal. You need to be comfortable with the Linux command line: filesystem navigation, package management, processes, and logs. Day-to-day operations like lxc-ls, lxc-start, and lxc-attach are pure CLI, so the ability to read terminal output and find solutions from error logs is your main asset.

#User and Permissions

The concepts of user, group, permission, and root are the heart of LXC. Privileged containers run the same root as the host, while unprivileged containers map the container's root to a regular user on the host through idmapping (we'll dig into this in episodes 5 and 15). Without understanding sudo, chown, and subuid, you'll have a hard time grasping why unprivileged containers are far safer.

#Basic Networking: Bridge and veth

LXC uses a bridge (e.g. lxcbr0) to connect containers to the network, and veth pairs to give every container a virtual interface. Understand the concepts of IP, subnet, NAT, and routing first. These will be used throughout starting from episode 6, including when you configure static IPs and port forwarding.

#Software & Hardware to Prepare

#Linux Host

Use a Linux host with full support for unprivileged containers. Ubuntu is recommended because it has full support for user namespaces and idmapping. Other distributions like Debian, Fedora, or Arch also work, as long as the kernel is modern and the required features are enabled.

#lxc Package and Tooling

For this series we use LXC 7.0 LTS (released April 30, 2026, supported until June 2031). The lxc package on Ubuntu includes all the tooling we need: lxc-create, lxc-start, lxc-attach, lxc-snapshot, lxc-copy, lxc-checkconfig, and lxc-ls. The version can be verified with:

lxc --version

#Modern Kernel

LXC needs a Linux kernel that supports namespaces, cgroups, and overlayfs. Kernel ≥ 5.x is the minimum viable baseline, and 6.x is much better because cgroup2 and user namespaces are far more mature. Check your kernel:

uname -r
uname -m

#Setting Up the Environment

Install the LXC package along with its dependencies:

sudo apt update
sudo apt install lxc

This package pulls in liblxc1 (the core C library), templates, and configuration scripts. Check that the lxcbr0 network daemon is ready to use — on Ubuntu, the package provides the lxc-net configuration that automatically creates the default bridge:

ip addr show lxcbr0

If it doesn't appear yet, start the lxc-net service:

sudo systemctl enable --now lxc-net

#Verifying the Environment

Run a thorough verification before moving on to the next episode:

lxc-checkconfig

This command prints the list of kernel features LXC requires — namespaces (user, pid, net, uts, ipc, mount), cgroups (with cgroup2), and overlayfs. Every line should show enabled:

lxc --version
uname -r
ip addr show lxcbr0

#Prerequisite Summary

What you should have prepared in episode 0:

• Linux skills: CLI, user/permissions, and basic networking (bridge, veth).
• Host: Linux with a modern kernel (≥ 5.x, ideally 6.x) and full unprivileged support.
• Packages: lxc 7.0 LTS installed along with the tooling and lxc-net.
• Verification: lxc-checkconfig passes for namespaces, cgroups, and overlayfs.

If anything isn't in place yet, complete it before continuing. The 22 episodes ahead will go much more smoothly with this solid footing.

#Closing

Key takeaways:

• LXC is a system container: the entire distribution runs on the same host kernel.
• Linux CLI, permissions, and bridge/veth networking are mandatory foundations.
• Prepare a Linux host (Ubuntu recommended), the lxc 7.0 LTS package, and kernel ≥ 5.x.
• lxc-checkconfig is your first verification gate.
• Make sure lxcbr0 exists as the default network bridge.

In the next episode 1 we'll cover the history, background, and why you need LXC — from its initiation by IBM and kernel developers in 2008, its evolution under the Linux Containers project, to the real reasons why system containers are needed in the modern world. Make sure your environment is ready, because the Learn LXC journey has just begun!