Proxmox LXC Containers: Lightweight Virtualization Done Right

VMs vs Containers on Proxmox

Proxmox VE supports both full VMs (KVM) and system containers (LXC). While VMs virtualize the hardware, LXC containers share the host kernel — making them dramatically more efficient for most server workloads.

The Density Advantage

Why LXC Over Docker?

Docker containers are stateless, ephemeral, and designed for microservices. LXC containers are system containers — they behave like full VMs with systemd, SSH, and persistent state.

Getting Started with LXC on Proxmox

Creating a Container

Via the Proxmox web UI:

• Datacenter → your_node → Create CT
• Select a template (Ubuntu 24.04, Debian 12, Alpine)
• Allocate CPU cores, RAM, and disk
• Configure networking (DHCP or static)

Or via CLI:

# List available templates
pveam available

# Download an Ubuntu template
pveam download local ubuntu-24.04-standard_24.04-2_amd64.tar.zst

# Create the container
pct create 100 \
  local:vztmpl/ubuntu-24.04-standard_24.04-2_amd64.tar.zst \
  --rootfs local-lvm:8 \
  --cores 2 \
  --memory 2048 \
  --net0 name=eth0,bridge=vmbr0,ip=dhcp \
  --hostname my-ct

# Start it
pct start 100

# Enter the shell
pct enter 100

Post-Creation Setup

# Set root password
pct set 100 --password

# Assign a static IP
pct set 100 --net0 name=eth0,bridge=vmbr0,ip=192.168.1.100/24,gw=192.168.1.1

# Mount a bind mount from the host
pct set 100 --mp0 /storage/data,mp=/mnt/data

# Set resource limits
pct set 100 --memory 4096 --swap 1024 --cores 4

Production Layout

┌──────────────────────────────────────┐
│         Proxmox Host (Debian)        │
│  ┌────────┐ ┌────────┐ ┌──────────┐ │
│  │ LXC 101 │ │ LXC 102 │ │ LXC 103  │ │
│  │  DNS    │ │  DB     │ │  Web     │ │
│  │ (PiHole)│ │(Postgres│ │ (Nginx + │ │
│  │         │ │ + Redis)│ │  Next.js)│ │
│  └────────┘ └────────┘ └──────────┘ │
│  ┌────────┐ ┌────────┐ ┌──────────┐ │
│  │ LXC 104 │ │ LXC 105 │ │ LXC 106  │ │
│  │  VPN    │ │  CI/CD  │ │  Backup  │ │
│  │ (WG)   │ │ (Drone) │ │ (Borg)   │ │
│  └────────┘ └────────┘ └──────────┘ │
└──────────────────────────────────────┘

Networking Patterns

Bridge Networking (Default)

Containers get IPs on the same subnet as the host — they're first-class citizens on your LAN.

# /etc/network/interfaces on Proxmox host
auto vmbr0
iface vmbr0 inet static
  address 192.168.1.10/24
  gateway 192.168.1.1
  bridge-ports eno1
  bridge-stp off
  bridge-fd 0

NAT Networking

Containers share the host's IP via NAT — useful when you have limited public IPs.

pct set 100 --net0 name=eth0,bridge=vmbr0,firewall=1
# Set up NAT via iptables on the host

Backup and Snapshots

# Snapshot (live, with RAM)
pct snapshot 100 pre-upgrade --description "Before Postgres 16 upgrade"

# Backup to Proxmox Backup Server
vzdump 100 --compress zstd --mode snapshot --storage pbs

# Restore
pct restore 100 /var/lib/vz/dump/vzdump-lxc-100-2026_07_02.tar.zst

Resource Optimization

Memory

LXC containers use no memory overhead beyond the processes running inside. A tiny Alpine container running a single service uses ~15MB RAM.

# Limit memory hard and soft
pct set 100 --memory 2048 --swap 512

# View actual memory usage
pct status 100 --verbose

Disk

Use .raw disk images on ZFS or LVM-thin for best performance with snapshots.

# Move rootfs to a different storage
pct move-volume 100 rootfs local-zfs

# Resize rootfs online
pct resize 100 rootfs +4G

When to Use LXC vs KVM

Conclusion

LXC containers on Proxmox give you the density and performance of containers with the management experience of full VMs. For most Linux server workloads — web services, databases, DNS, monitoring — they're the right default choice.