How to Allocate More RAM to a Minecraft Server on Linux? Step-by-Step Guide

Running a Minecraft server on Linux offers unparalleled control and stability, making it a popular choice for hosting both small and large-scale servers. However, one of the most important factors in maintaining optimal server performance is ensuring that enough RAM is allocated. Allocating more RAM permits the server to handle more players, complex worlds, & mods without lag or crashes. In this guide, we’ll walk you through the steps on how to allocate more RAM to a Minecraft server on Linux system.

Why Allocating More RAM is Important

Minecraft servers use RAM to process data, such as world generation, player movements, and mod calculations. Insufficient RAM can lead to:

• Lag and stuttering during gameplay.
• Slow chunk loading.
• Crashes, particularly with mods or high player counts.

By allocating the correct amount of RAM, you can:

• Improve overall server performance.
• Reduce latency for players.
• Enable the server to handle larger worlds and more mods.

Prerequisites

Before allocating more RAM, ensure the following:

1. 1. Java 64-bit is Installed:
      • The Minecraft server runs on Java. A 64-bit version is required to allocate more than 2 GB of RAM.
      • To check your Java version, run:

        java -version

        The output should indicate a 64-bit version.

   2. Sufficient RAM is Available:
      • Check your system’s total and available RAM using:

        free -h

   3. Minecraft Server Files are Set Up:
      • Ensure you have the server JAR file downloaded and ready.

How Much RAM Should You Allocate?

The amount of RAM to allocate depends on your server’s want:

1. 1. Vanilla Minecraft (No Mods):
      • 1-2 GB for small servers (up to 5 players).
      • 3-4 GB for larger servers (10+ players).
   2. Modded Minecraft:
      • 4-6 GB for light modpacks (20-30 mods).
      • 8-10 GB for heavy modpacks (50+ mods).
   3. Large Multiplayer Servers:
      • 8-16 GB for 20+ players or heavy modding.

Steps How to Allocate More RAM to a Minecraft Server on Linux

Here’s a step-by-step guide to allocating more RAM to your Minecraft server on Linux:

1. Edit the Server Startup Script

The startup script is used to launch the server and define its RAM allocation.

1. 1. Open a terminal & navigate to your Minecraft server directory:

      cd /path/to/your/minecraft/server

   2. Locate or create the startup script (e.g., start.sh). If it doesn’t exist, create one using a text editor like nano:

      nano start.sh

   3. Add the following command to the script:
      java -Xms1G -Xmx4G -jar server.jar nogui
      • -Xms1G: Sets the initial amount of RAM allocated (1 GB in this example).
      • -Xmx4G: Sets the maximum amount of RAM locate (4 GB in this example).
      • server.jar: Replace this with the actual name of your server’s JAR file.
      • nogui: Disables the graphical user interface for good performance.
   4. Save & finish the file (Ctrl+O, then Ctrl+X in nano).
   5. Make the script executable:

      chmod +x start.sh

2. Start the Server with the New Allocation

Go to the startup script to start your server with the updated RAM allocation:

./start.sh

3. Verify RAM Allocation

To ensure the server is using the allocated RAM, check the server logs or use tools like htop to monitor memory usage:

htop

Automating RAM Allocation with Systemd

For a more robust setup, you can create a systemd service file to manage your server. This approach ensures the server restarts automatically after crashes or reboots.

1. 1. Create a new service file:

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

   2. Add the following content:

      [Unit]
      Description=Minecraft Server
      After=network.target
      [Service]
      User=your-username
      WorkingDirectory=/path/to/your/minecraft/server
      ExecStart=/usr/bin/java -Xms1G -Xmx4G -jar server.jar nogui
      Restart=on-failure
      [Install]
      WantedBy=multi-user.target

      • Replace your-username with your Linux username.
      • Update WorkingDirectory & ExecStart paths to match your server setup.
   3. Save and close the file (Ctrl+O, then Ctrl+X).
   4. Reload the systemd daemon and enable the service:

      sudo systemctl daemon-reload
      sudo systemctl enable minecraft

   5. Start the server:

      sudo systemctl start minecraft

   6. Check the service status:

      sudo systemctl status minecraft

Optimizing Your Server’s Performance

Allocating more RAM is just one step in optimizing your Minecraft server. Here are additional tips:

1. Optimize Java Settings

Use advanced Java flags to improve performance. For example:

java -Xms4G -Xmx8G -XX:+UseG1GC -XX:+UnlockExperimentalVMOptions -XX:MaxGCPauseMillis=50 -jar server.jar nogui

• -XX:+UseG1GC: Enables the G1 garbage collector for better memory management.
• -XX:MaxGCPauseMillis=50: Reduces pauses caused by garbage collection.

2. Adjust Server Properties

Edit the server.properties file to reduce resource usage:

• Lower view-distance to decrease the number of chunks loaded per player.
• Disable unused features, like spawn-animals or spawn-npcs.

3. Monitor Resource Usage

Usage tools like htop or top to monitor CPU & RAM use. Identify and address bottlenecks promptly.

4. Use Performance Mods

Install performance-enhancing mods, such as:

• Fabric or Paper: Lightweight server frameworks that optimize performance.
• Phosphor: Improves lighting engine performance.
• Lithium: Enhances server-side performance.

Common Issues and Solutions

1. Server Fails to Start After Allocating RAM

• Ensure you’re using a 64-bit version of Java.
• Verify that the allocated RAM doesn’t exceed your system’s available memory.

2. High RAM Usage Despite Allocation

• Optimize mods and plugins to reduce resource consumption.
• Monitor memory usage and adjust allocation as needed.

3. Java Errors or Crashes

• Update to the latest version of Java.
• Use stable and compatible versions of mods and plugins.

Conclusion

Allocating more RAM to your Minecraft server on Linux is a straightforward process that can significantly enhance performance, especially for modded or multiplayer servers. By following this guide, you can ensure your server runs smoothly and provides an enjoyable experience for all players. Remember to monitor performance regularly and adjust settings as needed to optimize your server further. With the right configuration, your Minecraft server will be ready to handle anything you throw at it!