Host a Minecraft Server on an Old PC¶
A spare Windows 10/11 or Linux computer can be a good home for a small Minecraft Java world. This guide helps you check the hardware, keep it online, and protect your saves. Use First Swarm Server for the full launch steps.
Step 1: Check your old PC can handle it¶
For a small vanilla server, plan for:
- 2 CPU cores and 4 GiB of memory available to the game server;
- additional memory for the operating system, Docker or Podman, and other apps;
- enough free disk for the game, world, logs, and several backups; and
- a stable power supply and internet connection.
An 8 GB machine gives you more room than a 4 GB machine, but available memory matters more than total memory. Large worlds, high view distances, many players, and modpacks can need considerably more resources. Start with a small group and check actual use during play.
The hardware checker can help you compare your available resources with the game's starting requirements.
Step 2: Prepare the host network and machine¶
Use Windows 10/11 with Docker Desktop in Linux-container mode, or Linux with Docker Engine or rootful Podman. Prefer wired Ethernet and close other demanding applications before hosting.
For a direct internet connection, reserve a stable local IP for the computer in your router and prepare to forward the assigned game port. A supported managed relay avoids those inbound router rules. Both paths still need a working internet connection.
Step 3: Install Docker and the Swarm Host agent¶
Follow the installation guide for your operating system. Generate a one-use enrollment code from Profile → Connect a host and paste it into the installer's hidden prompt to connect the machine to your account. Each code connects one host and expires after 15 minutes.
When it finishes, open Swarm hosts and check that the computer is online and its container runtime is ready. On Windows, Docker working in your own PowerShell session does not necessarily mean the agent service can reach it; use the Windows guide if the host reports a runtime blocker.
Step 4: Make a realistic uptime plan¶
Your server is available only while the computer and connection are working.
- Disable sleep while hosting.
- Schedule operating-system updates and restarts outside play sessions.
- Avoid large downloads or other heavy work while people are playing.
- Consider a UPS if brief power cuts are common.
On Windows, Docker Desktop normally starts after the installation user signs in. Plan for that sign-in after a reboot; the agent service starting alone does not make Docker's Linux engine available.
Step 5: Launch your first Minecraft Java server¶
Follow First Swarm Server. Start with 2 CPU cores, 4 GiB of server memory, a small group of 2–4 players, and a vanilla or lightly customized world. Leave settings you do not recognize at their defaults.
Keep Authenticate with Mojang enabled for a normal public server. Add large modpacks or increase view distance only after checking how the machine handles your first sessions.
Step 6: Verify the server is reachable¶
Wait for the server to report running and for the Minecraft status check to
pass. Then copy the player address from the Swarm Server page and join through
Minecraft Java's Multiplayer menu.
Ask a friend on another internet connection to join too. A successful local connection does not test the path that players outside your home will use.
Step 7: Router and firewall expectations¶
If the server uses a managed relay, share its displayed player address. You do not need to forward the game port on your home router for that relay path.
For direct access, forward the assigned TCP host port to the computer's local
IP and allow it through the host firewall. Use the port shown by Swarm Hosts;
it may differ from Minecraft's default 25565.
Carrier-grade NAT (CGNAT) can prevent direct inbound connections even when the router rule is correct. Use a supported relay or consult your ISP about direct public access. See Relays and Port Forwarding for more help.
Step 8: Backups and world files (do this before mods)¶
Open Files & Backups → Backups to create a manual backup before editing configuration or adding mods. Set a backup schedule once the world is working.
Minecraft's default world is stored under /data/world inside the container.
Use the file manager for changes and restart the server when the game guide
requires it.
Keep enough disk space for your worlds and backup retention. A backup on the same disk will not protect you if that disk fails, so download a separate copy of important worlds to another device and periodically test a restore.
Step 9: Early Access limits to plan around¶
Available settings, versions, and content tools depend on the server type and current release. Start with the choices shown in the launch form and consult the Minecraft guide before adding content.
A healthy status check helps confirm readiness. Joining the server and checking the world yourself is still the best way to verify the experience for players.
Step 10: Troubleshooting and support¶
If startup stalls or players cannot join, open Troubleshooting. If you need help, use the Support Checklist and include the host name, server status, and connection-check result. Keep account details and server identifiers in a private support conversation.
Next action¶
Launch a small world, test with a friend outside your home network, and create a backup before expanding the setup.