Minecraft Server Setup

Last Edit: 2024.12.20

Debian / Ubuntu

Overview

Setup a PaperMC Minecraft server and complete initial configuration on a Debian-based system.

Assumptions

Initial System Setup completed.
Logged in as administrative user.

Update

Before getting started, update package repositories and apply upgrades for the latest patches.

# Debian
sudo apt update
sudo apt upgrade

Install Java

Minecraft utilizes Java and requires a Java Runtime Environment (JRE) to be installed on the system. If you intend on running Minecraft 1.17+, make sure you install Java version 16 or higher.

OpenJDK

OpenJDK is an open-source implementation of the Java Platform SE, distributed under the GPLv2 license. If you wish to use OracleJDK instead, be aware you must purchase a license for commercial and production use. Select the required OpenJDK version below based on the Minecraft version that will be used.

Minecraft 1.20.5 - 1.21 (OpenJDK 21 LTS)

sudo apt install openjdk-21-jre-headless

Minecraft 1.16.5 - 1.20.4 (OpenJDK 17 LTS)

sudo apt install openjdk-17-jre-headless

Minecraft 1.12 - 1.16.4 (OpenJDK 11 LTS)

sudo apt install openjdk-11-jre-headless

Minecraft 1.8 - 1.11 (OpenJDK 8 LTS)

sudo apt install openjdk-8-jre-headless

Verify

Verify that Java installed without issue by checking the version.

java -version

The status should resemble the following.

openjdk version "17.0.2" 2022-01-18
OpenJDK Runtime Environment (build 17.0.2+8-Debian-1deb11u1)
OpenJDK 64-Bit Server VM (build 17.0.2+8-Debian-1deb11u1, mixed mode, sharing)

Create System User

Add a new minecraft system user and map the home directory to /opt/minecraft.

sudo useradd --system --user-group --create-home --home /opt/minecraft --shell /sbin/nologin minecraft

Execute commands as the user using su.

sudo su -s /bin/bash minecraft -c "COMMAND_TO_RUN"

Alternatively, switch to the user with su.

sudo su -s /bin/bash - minecraft

Create a few required directories (backups, bin, log, server) in the new minecraft users home directory, /opt/minecraft.

mkdir /opt/minecraft/{backups,bin,log,server}

Install Minecraft

With OpenJDK up and running, Minecraft can now be installed. This bit covers the process for installing PaperMC, instead of the vanilla release from Mojang.

Install PaperMC

PaperMC provides extra configuration options, offers performance improvements, and allows you to install Paper / Spigot / Bukkit plugins. This is a server-side change, and requires no additional configuration for users client-side. Learn more about PaperMC at papermc.io. To install the official release instead, the latest version can be found at minecraft.net/download/server.

Download PaperMC to the /opt/minecraft/server directory. The latest version can be found at papermc.io/downloads, and a list of download links for previous versions can be found at papermc.io/legacy. A few different versions are listed below.

Minecraft 1.21.4

wget https://api.papermc.io/v2/projects/paper/versions/1.21.4/builds/15/downloads/paper-1.21.4-15.jar --directory-prefix /opt/minecraft/server

Minecraft 1.18.2

wget https://api.papermc.io/v2/projects/paper/versions/1.18.2/builds/388/downloads/paper-1.18.2-388.jar --directory-prefix /opt/minecraft/server

Minecraft 1.16.5

wget https://api.papermc.io/v2/projects/paper/versions/1.16.5/builds/794/downloads/paper-1.16.5-794.jar --directory-prefix /opt/minecraft/server

Minecraft 1.12.2

wget https://api.papermc.io/v2/projects/paper/versions/1.12.2/builds/1620/downloads/paper-1.12.2-1620.jar --directory-prefix /opt/minecraft/server

Copy the downloaded jar file to paper.jar for ease of use in commands and configuration. To install an updated version, overwrite the paper.jar file in the future. Consider copying instead of moving so there is a record of previously used versions incase a rollback is needed.

cp /opt/minecraft/server/paper-1.21.4-15.jar /opt/minecraft/server/paper.jar

Start Paper to create the eula.txt and server.properties files. You will receive warning and error messages, this is expected behavior.

java -Xmx1024M -Xms512M -jar /opt/minecraft/server/paper.jar nogui

The output will resemble the following. This error is expected.

Loading libraries, please wait...
[02:22:20 ERROR]: Failed to load properties from file: server.properties
[02:22:20 WARN]: Failed to load eula.txt
[02:22:20 INFO]: You need to agree to the EULA in order to run the server. Go to eula.txt for more info.

Install MCRCON

MCRCON is an implementation of the RCON (Remote CONsole) protocol designed specifically for Minecraft. MCRCON will allow you to execute console commands via scripts, as other system users, and from remote systems.

Create an mcrcon directory in the /opt/minecraft/bin directory. As the path suggests MCRCON will be installed here.

mkdir /opt/minecraft/bin/mcrcon

Download the latest release from MCRON’s GitHub repository. At the time of writing this was version 0.7.2. The most recent version can be found at github.com/Tiiffi/mcrcon/releases/latest.

wget https://github.com/Tiiffi/mcrcon/releases/download/v0.7.2/mcrcon-0.7.2-linux-x86-64.tar.gz --directory-prefix /tmp

Extract the downloaded release using tar to the /opt/minecraft/bin/mcrcon directory.

tar -xvf /tmp/mcrcon-0.7.2-linux-x86-64.tar.gz -C /opt/minecraft/bin/mcrcon

Set the permissions of the mcrcon directory so only the minecraft user / group can interact with it.

chmod -R 750 /opt/minecraft/bin/mcrcon

Configure Minecraft

Complete initial configuration after finishing installation.

EULA

Start by accepting the Minecraft EULA. Open the eula.txt file in your text editor of choice.

nano /opt/minecraft/server/eula.txt

After reading the Minecraft EULA, set eula=true.

#By changing the setting below to TRUE you are indicating your agreement to our EULA (https://account.mojang.com/documents/minecraft_eula).
#You also agree that tacos are tasty, and the best food in the world.
#Sun Apr 20 04:20:42 UTC 2024
eula=true

Server Properties

Next up is the server.properties file. This is where you will find all the default configurable options for your server. Configuration for enabling RCON is detailed below as it relates to MCRCON. Full customization of this is outside of the scope of this bit, please refer to the Minecraft Wiki for more information on what each option does. Open the server.properties file in your text editor of choice.

nano server.properties

Find the lines relating to RCON and set them as follows. This will set the port, the password used to connect, and enable the remote console. Generate and save the created password, do not set enable-rcon to true until a secure password has been configured.

rcon.port=25575
rcon.password=Generated_Secure_Password
enable-rcon=true

Setup Backups

Backups are important for a Minecraft server, especially if you are using plugins or opening it up to the public. In this section we will automate the process of creating daily backups that are stored for one week.

Start by creating a backup script in the /opt/minecraft/bin directory.

nano /opt/minecraft/bin/backup.sh

Enter in the following template script and adjust it to suit your server. As written, the script will create a backup /opt/minecraft/server as an archive named server-YYYY-MM-DD-HH-MM.tar.gz and store it in /opt/minecraft/backups. It will also delete any tar.gz files in the backups directory that are older than 7 days.

Replace Generated_Secure_Password in the consolemc function to match the password set in the server.properties file.
Change the serverDir, backupDir, and dateFormat if necessary.

#!/bin/bash
# Minecraft Backup Script

# MCRCON Command
function consolemc {
  /opt/minecraft/bin/mcrcon/mcrcon -H 127.0.0.1 -P 25575 -p Generated_Secure_Password "$1"
}

# Server Directory
serverDir="/opt/minecraft/server"
# Backup Directory
backupDir="/opt/minecraft/backups"
# Date Format (YYYY-MM-DD-HH-MM)
dateFormat=$(date +%F-%H-%M)
# File Prefix
filePrefix="minecraft-server-"

# Disable Disk Writes
consolemc "save-off"
# Flush Pending Writes
consolemc "save-all"
# Create Backup Archive
tar -cpzf $backupDir/$filePrefix$dateFormat.tar.gz $serverDir
# Enable Disk Writes
consolemc "save-on"

# Delete Backups (> 7 days old)
find $backupDir -type f -mtime +7 -wholename "$backupDir/$filePrefix*.tar.gz" -exec rm {} \;

Change the permissions of the script so only the minecraft user can interact with it.

chmod 750 /opt/minecraft/bin/backup.sh

With the script setup, create a cron job to execute the script once a day. Open up the crontab to configure this.

crontab -e

Add the following to the bottom of the file. This will execute the script you just created everyday at 3:00 AM, and create a log of the most recent script execution in /opt/minecraft/bin/backup.log.

# Minecraft Backup Script
0 3 * * * /opt/minecraft/bin/backup.sh > /opt/minecraft/log/backup.log 2>&1

Configure Server

Time to configure some server processes. With Minecraft installed and basic setup complete, logout of the minecraft user and switch back to your administrative account.

logout

Permissions

Add your current user to the mincecraft group, allowing it to navigate the /opt/minecraft directory. By default, files and plugins need to be edited with the minecraft user or sudo.

sudo usermod -aG minecraft $USER

Firewall

Before being able to connect to the server from a Minecraft game client, you must allow connections to port 25565.

sudo ufw allow proto tcp to any port 25565

Systemd

To better control the state of the Minecraft application, setup Minecraft as a service with a systemd unit file. Create the file using your text editor of choice.

sudo nano /etc/systemd/system/minecraft.service

Enter in the following configuration and adjust it to suit your server. For more information about systemd unit configuration, refer to the freedesktop.org documentation.

Verify the User= and WorkingDirectory= definitions are correct.
Set the flags Xmx1024M and Xms512M in ExecStart= based on your available system RAM. The Xmx flag is the maximum amount of RAM the Minecraft application can use, and the Xms flag is the minimum amount. To allow Minecraft to use 8GB of RAM you could use Xmx8192M and Xms2048M. Set the maximum value to be at least 1GB lower than the total amount of RAM available on your system.
Replace Generated_Secure_Password in ExecStop= to match the password set in the server.properties file.

[Unit]
Description=Minecraft
After=network.target

[Service]
User=minecraft
WorkingDirectory=/opt/minecraft/server
Nice=1
SuccessExitStatus=0 1
NoNewPrivileges=true
ProtectSystem=full
ProtectHome=true
PrivateDevices=true
ExecStart=/usr/bin/java -Xmx1024M -Xms512M -jar paper.jar nogui
ExecStop=/opt/minecraft/bin/mcrcon/mcrcon -H 127.0.0.1 -P 25575 -p Generated_Secure_Password stop

[Install]
WantedBy=multi-user.target

Reload systemd so it is aware of the changes made.

sudo systemctl daemon-reload

The Minecraft application can now be controlled with the systemctl command. The restart directive will not work, use the stop and start commands separately if you with to restart the server.

# Start Minecraft
sudo systemctl start minecraft
# Stop Minecraft
sudo systemctl stop minecraft

Connect

The Minecraft server is now setup and ready to go. Start installing plugins, and configuring everything to your heart’s desire.

Console

To start a Minecraft console session with MCRCON, use the following command with the -t flag. Replace Generated_Secure_Password with the password set in the server.properties file.

/opt/minecraft/bin/mcrcon/mcrcon -H 127.0.0.1 -P 25575 -p Generated_Secure_Password -t

To issue a single command without opening a console session, enter the command you wish to run instead of the -t flag.

/opt/minecraft/bin/mcrcon/mcrcon -H 127.0.0.1 -P 25575 -p Generated_Secure_Password "stop"

Game Client

Spin up the Minecraft launcher and make sure to use the same game version as your server. Head over to the Multiplayer tab and select Add Server. In the Server Address field put the IP address of your server, or the domain name pointed at it, and select Done. If you configured any port besides 25565 in the server.properties file, you must specify that after the address. Your server will now be on the Play Multiplayer list, simply select it and hit Join Server.

Errors

Invalid Java Version 1.17

On Paper 1.17, the -DPaper.IgnoreJavaVersion=true flag must be included in the start command because Paper did not officially support Java 17 yet. Refer to the following example, replacing the memory values as required.

java -DPaper.IgnoreJavaVersion=true -Xmx1024M -Xms512M -jar /opt/minecraft/server/paper.jar nogui

References

Fandom. “Minecraft Wiki.” 2024. ↩︎