Beszel — Lightweight Server Monitoring

Most monitoring tools ask you to choose between two bad options: pay for a SaaS dashboard that phones home all your server metrics, or run a full observability stack that consumes more resources than the apps you're trying to monitor. Beszel is a third option.

Beszel is an open-source monitoring platform built around a hub-and-agent model. The hub runs on one server and provides the dashboard; lightweight agents run on every server you want to monitor and report back to the hub. The entire agent process uses roughly 23 MB of RAM at idle. On a $4/month RamNode VPS with 512 MB of RAM, that leaves you with nearly all of it for your actual workloads.

What Beszel Monitors

• • System metrics — CPU usage, memory, disk I/O, network throughput
• • Per-container metrics — Docker and Podman container stats without additional exporters
• • Historical data — Retention configurable from 1 day to indefinite, stored in an embedded SQLite database
• • Multi-server overview — All your servers visible in a single dashboard pane
• • Alerting — CPU, memory, disk, and network thresholds with notifications via ntfy, Gotify, Slack, Discord, Pushover, Telegram, and email

What it does not do: application-level tracing, log aggregation, or distributed tracing. Those use cases are covered later in this series. Beszel is intentionally scoped to host-level and container-level metrics.

Architecture Overview

RamNode VPS A (hub server)
  └── Beszel Hub (Docker container)
        └── Web UI + API
        
RamNode VPS B, C, D... (monitored servers)
  └── Beszel Agent (single binary, ~23 MB RAM)
        └── Reports metrics → Hub over SSH tunnel

The agent does not open a port on the monitored server. It communicates outbound to the hub over an encrypted SSH connection. This means you do not need to open additional firewall rules on your monitored servers — only the hub needs to be reachable.

Deploy the Hub

mkdir -p /opt/beszel && cd /opt/beszel

services:
  beszel:
    image: henrygd/beszel:latest
    container_name: beszel
    restart: unless-stopped
    ports:
      - "8090:8090"
    volumes:
      - ./beszel-data:/beszel_data

docker compose up -d

beszel.yourdomain.com {
    reverse_proxy localhost:8090
}

server {
    listen 443 ssl;
    server_name beszel.yourdomain.com;

    ssl_certificate /etc/letsencrypt/live/beszel.yourdomain.com/fullchain.pem;
    ssl_certificate_key /etc/letsencrypt/live/beszel.yourdomain.com/privkey.pem;

    location / {
        proxy_pass http://127.0.0.1:8090;
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection "upgrade";
    }
}

Add the Hub Server as Its Own Agent

The hub server should monitor itself. In the Beszel dashboard, click Add System. You will be shown a public key to authorize and the agent installation command.

For the hub server itself, use the Docker-based agent:

  beszel-agent:
    image: henrygd/beszel-agent:latest
    container_name: beszel-agent
    restart: unless-stopped
    network_mode: host
    volumes:
      - /var/run/docker.sock:/var/run/docker.sock:ro
    environment:
      PORT: 45876
      KEY: "PASTE_YOUR_PUBLIC_KEY_HERE"

The KEY value comes from the dashboard when you click Add System. Restart the stack:

docker compose up -d

Back in the dashboard, finish adding the system using localhost as the hostname and 45876 as the port.

Add Remote Agents to Additional Servers

For every other VPS you want to monitor, the agent runs as a standalone binary rather than Docker. This keeps the footprint smaller.

curl -sL https://raw.githubusercontent.com/henrygd/beszel/main/supplemental/scripts/install-agent.sh \
  -o /tmp/install-agent.sh && chmod +x /tmp/install-agent.sh

/tmp/install-agent.sh -p 45876 -k "PASTE_PUBLIC_KEY_HERE"

systemctl status beszel-agent

Monitor Docker Containers

If the server running the agent also runs Docker containers, Beszel automatically picks them up. No additional configuration is needed. In the system detail view, switch to the Containers tab to see per-container CPU, memory, and network stats.

For the binary agent, add the agent user to the docker group if needed:

usermod -aG docker beszel-agent
systemctl restart beszel-agent

Configure Alerts

Beszel's alerting is configured per-system and per-metric. In the dashboard, click the bell icon on any system.

Available alert triggers

Notification channels

Go to Settings > Notifications to add a channel. Beszel supports ntfy, Gotify, Slack, Discord, Pushover, Telegram, and email.

For a RamNode fleet, a Discord webhook is the quickest path to working alerts:

1. In your Discord server, go to Channel Settings > Integrations > Webhooks
2. Create a new webhook and copy the URL
3. In Beszel Settings > Notifications, select Discord and paste the URL
4. Save and click Test to verify delivery

Recommended alert thresholds

Firewall Considerations

The hub needs to reach port 45876 on each agent server. If your agents are behind UFW:

ufw allow from HUB_IP to any port 45876

If you prefer to keep things locked down further, Tailscale or WireGuard between hub and agents is a solid option — Beszel works fine over a private mesh network.

Keeping Beszel Updated

The hub image follows latest by default. To update:

cd /opt/beszel
docker compose pull
docker compose up -d

For the binary agent:

curl -sL https://raw.githubusercontent.com/henrygd/beszel/main/supplemental/scripts/install-agent.sh \
  -o /tmp/install-agent.sh && chmod +x /tmp/install-agent.sh
/tmp/install-agent.sh -p 45876 -k "YOUR_KEY"

The install script handles updating in-place.

Resource Usage Benchmark

On a RamNode VPS running the hub with 3 agents reporting in:

This makes Beszel viable even on the smallest RamNode plans. You can dedicate one low-cost VPS as your monitoring hub and agents on your production servers will barely register in your resource accounting.

What's Next