**Notice - This documentation is no longer updated.

Effective July 13, 2023 - The documentation on this page is made freely available under the Attribution 4.0 International (CC BY 4.0) License.

You are free to use and distribute the documentation as per the terms of the license.

Intro Image

Build a Modded Minecraft Server on Linux

WARNING: Only download Forge from the official site at files.minecraftforge.net. Always beware of scam sites.

TL/DR - Modded Linux Condensed Version - For Returning Users

Building a full Linux vanilla server? See the Linux server install documentation.
Building on Raspberry Pi 4? See the Raspberry Pi 4 install documentation.

Minecraft Server Version: 1.12.2
Minecraft Forge 1.12.2-
Java Version: OpenJDK version "1.8.0_312"

Approximate time to complete: 30 minutes depending on your server. This also depends on your comfort level working from the Linux command line. Give yourself plenty of time.

Get free hosting credits towards a dedicated server with DigitalOcean by using this link.

Step 1 - Install Java
Step 2 - Setup Your Environment
Step 3 - Download the Forge Installer file
Step 4 - Configure your new Modded Minecraft Server
Step 5 - Optional-- Configure Minecraft to start on bootup
Step 6 - Connect to Your Server
Step 7 - Hardening Your Minecraft Server if Visible on the Internet
Step 8 - Backup Your Server Frequently
Step 9 - Recovering a Corrupted World
Step 10 - Creating Automatic Backups

Donate Your donations keep this site ad free -- Thank You

Report errors in this guide. Your feedback is appreciated.

Things to consider...

These instructions are for building a modded Minecraft Java Edition Server. All players using your server must install the same mods locally on their own PC. Configuring your PC to play mods is outside the scope of this article.

These instructions won't work for PE or the Better Together version. The modding scene is almost entirely on the Java edition and you will need to be running Minecraft Java on PC (Windows, Linux or Mac) to connect to this server. You will not be able to connect to this with your Xbox or your Ipad or the Microsoft Windows 10 Edition.

Be careful when downloading mods. There are so many shady mod sites that use AdFly links that lead to porn ads, that rehost mods without permission from the authors and even host ads that lead to malware sites. It's a minefield, and for this reason, I highly recommend that you get your mods from CurseForge which uses the Twitch launcher. While Curse have a tonne of mods, they don't have everything. Minecraftforum.net seems fine too to get individual mods. I am sure there a other reputable places, but you are taking your chances.

You will also need the Forge Minecraft launcher to play mods. If you are new to mods, getting an account with Twitch/Curse and using their launcher and managing your mods there is much easier. You can't play on a modded server with the stock Mojang Launcher. You need to install Forge (or the Twitch Launcher) for the version you want to play.

Finally, these instructions are for version 1.12.2 of Minecraft. When it comes to mods version matters. There are many great mods at version 1.7.10 for example. No worries though, these instructions should work the same for any version you need. You just need to download the right version of Forge which I will get into later.

Why Linux and Not a Fully Managed Solution?

This is a valid question. A fully managed solution like one offered by the many dedicated Minecraft hosting companies out there can make sense. There is no need to secure the underlying Linux OS, this is all done for you. You get a nice graphical front end to manage your server, automated backups, DNS management to access your server, FTP access. They provide a GUI for managing your mods.

However, if you decide to go with a dedicated setup you can get a credit towards your server with DigitalOcean if you sign up through this referral link. Sizing of your server will depend on how many mods and users you intend to have.

Here are some of the reasons you may want to build your own;

1 - Maximum control right down to the OS level.
2 - Prefer working from the command line than from a Web browser to manage your server.
3 - High memory and cpu needs for your server and a VPS or dedicated server is cheaper than a higher end fully hosted solution.
4 - Have a server available which isn't costing you anything and a good internet link.
5 - Want to learn how to do it yourself from start to finish.
6 - Finally, the most important reason of all.....Because You Can!

Which Linux Distribution?

Recommending a specific Linux distribution as "the best option" is like recommending a religion as the "best one to follow". You will either be preaching to the converted or alienating the person you are having the discussion with.

For my purposes I like using Debian and its derivitaves. However I have used other distributions and have liked them as well. This guide uses Ubuntu Server 18.04 LTS using the apt package manager. When a package manager is called for, just substitute the relevant commands for your favorite distro. They are all good.

Root Access to Your Server

The instructions assume that you have root (Administrator) access to your server. For simplicity I assume you are logging in as the root user. All of these commands will also work with sudo. If running sudo from your user account then make sure to add it when necessary. I will not be using sudo in front of these command line arguments throughout the document.

Step 1 - Install Java

Minecraft Server version 1.12.2 requires Java 8 to run. You can install it on Ubuntu as follows;

a) Login to your server via ssh or open a console window if this is a Linux Desktop system.

via Linux:   ssh username@your_domain
via Windows: Connect using a SSH client such as Putty

b) Run the following command

    apt install openjdk-8-jdk

*** NOTE: If using these instructions to install later versions of Minecraft like 1.16 then you can install Java 11 as follows;

    apt install default-jre
c) Finally check your version to make sure all went well during install.
    i) java -version

You should see the following;

    openjdk version "1.8.0_312"
    OpenJDK Runtime Environment (build 1.8.0_312-8u312-b07-0ubuntu1~18.04-b07)
    OpenJDK 64-Bit Server VM (build 25.312-b07, mixed mode)

If after installing you still see a different verison of java, run the following command and select java-8-openjdk-amd64/jre/bin/java
    update-alternatives --config java

Step 2 - Setup Your Environment

a) This is a good time to do a full upgrade of your system. If using a Debian based system you can use apt, otherwise use your distributions package manager.
    apt update && apt -y upgrade
b) Install screen (This will be needed to run your minecraft server console while logged out of your Linux server).
    apt install screen

Step 3 - Download The Forge Installer

a) create the folder
    cd /opt
    mkdir minecraft
    cd minecraft

Now download the version 1.12.2 Forge Installer. Pick the Latest Installer file (not the Universal file) and copy it to your /opt/minecraft folder.

You should now have only one jar file in your /opt/minecraft folder.

Tip: If connecting to your server from a Windows based pc, use Filezilla or WinSCP to transfer the files to your Linux server

Step 4 - Configure your new Modded Minecraft Server

a) run the forge installer file with the --installServer flag.
    java -jar forge-1.12.2- --installServer
This will take a bit of time and will create a second file called forge-1.12.2-

Now run the newly created forge jar file as follows;

    assuming a server with 2048MB (2GB RAM)    
    cd /opt/minecraft && java -Xms1024M -Xmx2000M -jar /opt/minecraft/forge-1.12.2- nogui  
*Note: -Xms1024M and -Xmx2000M are parameters telling java to start with 1GB of ram as a minimum for the server jar file and let it grow to just under 2GB max as needed. If your server has more ram to dedicate then you can adjust these numbers. More players and more mods mean you need more. These are not constructs unique to Minecraft. Do a google search on (xms xmx jvm) and you will get some good information on how to manage a JVM's heap. From there you can make a better determination on what you should set this to for your servers resources and how you will be using your server.

For example, on a VPS with 1GB of ram I have set xms and xmx to 512M and 1008M respectively. So start the JVM with 512MB of ram and let it grow to just under 1GB max.

b) accept the EULA. The first time you try to run your minecraft server you will be required to accept the EULA.

    nano eula.txt
c) Change the following line to true and save the file
d) copy your mods to the newly created mods folder.

e) Run the server again to generate your world. World generation will take a little longer the first time. Subsequent server starts will be much quicker.
Before doing this, you can download the following server.properties file and replace the one that was created automatically. (or copy/paste directly to your existing server.properties file from the console).
This server.properties file will give you a standard survival world on normal difficulty.

Edit the file with your preferred seed if you have one and it will generate the world that you specify.
Minecraft Atlas is great site to find new interesting seeds. Although the site says Minecraft 1.8, the seeds are compatible with 1.12.2
View the Wiki for all server.properties configuration options.

    nano server.properties
    change the following line with your preferred seed directly after the = sign
    If you leave it blank Minecraft will generate a random world on first launch
On a low power system you can lower the view distance. Start with 10 for your modded server, and adjust it downward if you get some lag. If you have plenty of CPU and RAM you can increase it as well.

f) make things a little easier on yourself by using a script to start minecraft

    cd /opt && mkdir scripts
    cd scripts
    nano minecraft.sh

g) Copy and paste the following in your minecraft.sh file
    cd /opt/minecraft/ && java -Xms1024M -Xmx2000M -jar /opt/minecraft/forge-1.12.2- nogui
h) Save the file and make it executable
    chmod +x minecraft.sh
i) Start your server
    screen <---hit enter at the informational message
    To exit the screen session hit 'CTRL AD'

Step 5 - Optional-- Configure Minecraft to start on bootup.

a) Add a command to /etc/rc.local to start your Minecraft server everytime the server boots up.
    nano /etc/rc.local
Right before the last line 'exit 0' add the following command, save and exit the file. This will allow the minecraft server to start in a detached screen session when the server boots up.
    screen -dm -S minecraft /opt/scripts/minecraft.sh 

Note: rc.local still works on some Debian derivitaves such as Ubuntu 16.04LTS. On Debian proper and Ubuntu 18.04 LTS, rc.local has been deprecated. To re-enable rc.local you can simply re-create /etc/rc.local file as follows;
cd /etc
nano rc.local
in the rc.local file copy and paste the following
screen -dm -S minecraft /opt/scripts/minecraft.sh
exit 0
Save the file and make it executable
chmod +x rc.local

If that doesn't work you may have to re-enable the rc.local service. Use the following set of instructions. However this should not be necessary.

Also note that I have not tested this on Ubuntu 20.04LTS but you should be able to re-enable rc.local there as well.

b) To access your console after bootup use the following command;
    screen -r minecraft
    To exit the screen session use the following command

Note: Some people may question why I am using rc.local instead of an init script to start the minecraft server. I don't want to run the server in the background, I want a full screen session accessible to view and interact with the minecraft server console. If I want to stop the server I want to issue a stop command there, not from a script in init.d. Also rc.local is one line and is super easy. It just works well for this situation. I use init scripts for other things and they are great, but this is just a preference I have for a minecraft server. Do what works for you.

Step 6 - Connect to Your Server

If you have made it this far then I assume you have already been playing mods on local single player worlds. You already know how to install mods locally. If not then just make sure that you have the same mods running on your PC that you have installed on your server. Your server and local mods folders should have the same files in them.

If you have friends that want to join your server they will also need to have the same mods and mod versions on their computers. If they need help setting things up you can direct them to the How to Install and Play Mods page.

a) In Minecraft select the Multiplayer button

b) Click the Add Server button
c) Edit the Server Info as follows (insert the IP address of your Linux server)

Add Server Image

d) Enter your world for the first time and have fun!!!

New Server Image

Step 7 - Hardening Your Minecraft Server if Visible on the Internet

If you want friends to access the server from outside your home network you will have to forward external requests to port 25565 on your router to your server. Check the documentation for your router.

a) If you are installing this on a VPS or dedicated server you will most likely want to enable the firewall with netfilter/iptables. You should be blocking ports that are not used or that you do not want to expose to the internet. An example rule for a minecraft server would be as follows;

    /sbin/iptables -A INPUT -p tcp --dport 25565 -m state --state NEW -j ACCEPT
This rule says to accept all new tcp packet requests to the minecraft server listening on port 25565.

To help you get started please refer to my article on setting up The Linux Five Minute Firewall.

Note:If you are not comfortable doing this then a VPS or dedicated server solution may not be a good one for you. If you manage a full Linux server connected directly to the internet with a public IP address, it is your responsibility to ensure you are hardening and securing it properly. If this is not something you want to do then a fully managed solution with a Minecraft server hosting company may be a better option for you. They take care of all the dirty work like this.

b) Activate whitelisting. It is extremely important to activate whitelisting if your server is visible on the internet. Port 25565 is a popular port and is actively scanned by all kinds of people using automated scripts. They are looking for open servers so they can login and cause havoc on your world. Whitelisting will stop unauthorized users from joining your world.
In your server.properties set the following value to true;

Restart your minecraft server and run the following command at the console for each user you would like to allow.
    whitelist add minecraft_user1
    whitelist add minecraft_user2

To remove a user

    whitelist remove minecraft_user2   
When an unauthorized user tries to connect to your server they will simply get a message that they are not whitelisted and will be turned away.

Step 8 - Backup Your Server Frequently

To backup your server do the following;
    login to your server
    cd /opt
    tar -zcvf minecraft_backup.tar.gz minecraft
Copy the minecraft_backup.tar.gz to a safe location, preferably another computer. This file can be used to restore your world if needed. Get into the habit of doing this regularly. You can even use the cron scheduler to automate the process at a specified time each day as explained in Step 10.

Step 9 - Recovering a Corrupted World

The importance of regular backups cannot be overstated. It happens, you try to log into your awesome minecraft world and you see exception errors only. Or you enter the world and all kinds of things have disappeared, your sweet enchanted sword is gone, your diamonds chest is empty. Hours of work and play are now destroyed. Your world may have corrupted for any number of issues such as software problems or disk errors.

If you did your backups like we discussed in Step 8 then you are laughing. To restore your previous backup do the following;

Delete your existing minecraft folder

    cd /opt
    rm -r -f minecraft  
copy your previously saved minecraft.tar.gz file to your /opt folder.

restore your world

    tar -zxvf minecraft.tar.gz

That's it, restart your server and you have successfully restored from your last good backup. Any changes you made since that backup are gone, so it is important to do your backups regularly.

Step 10 - Creating Automatic Backups

These instructions will help you create automatic backups of your minecraft world, so that you don't have to worry about remembering. These instructions will do the following;

1) Provide a ready to use script to initiate the backup
2) Configure the cron scheduler to start the backup at 2:02am everyday
3) Name the backup day_of_week-minecraft-.tar.gz

This will create a 7 day rotation of backups with the oldest being overwritten with a new one.

a) Create your script.

    cd /opt/scripts
    nano mcbackup.sh
b) copy and paste this script into your mcbackup.sh file you have open in the nano editor. Change the dest= line to point to the folder you want your backups to reside in.

# Backup minecraft world to a
# specified folder.

# What to backup.  Name of minecraft folder in /opt

# Specify which directory to backup to.
# Make sure you have enough space to hold 7 days of backups. This
# can be on the server itself, to an external hard drive or mounted network share.
# Warning: minecraft worlds can get fairly large so choose your backup destination accordingly.

# Create backup archive filename.
day=$(date +%A)

# Backup the files using tar.
cd /opt && tar zcvf $dest/$archive_file $backup_files

c) Save the file by pressing CTRL-X and entering Y

d) Make the file executable

    chmod +x mcbackup.sh
Step 12 e) Test your script. Before creating the scheduled task ensure your script works


You should see the backup happening. Once completed open the file it created which should be in the location that you specified. Once you have confirmed that your backup works, create a scheduled task to automate the backups.

f) Create a scheduled task with the cron scheduler
Make sure you are logged in as root so that it writes to your root user crontab.

    crontab -e
Enter this line at the end of your root crontab and then save it.
    02 2 * * * /opt/scripts/mcbackup.sh &> /dev/null
This will create your backup every day at 2:02 am. That's it, in your folder where you specified your backups to be created you will have the following after one week;

Every day your oldest file will be replaced with the new backup giving you a seven day rotation of backups.

That's it! Now have fun! I hope these instructions were helpful and that you learned a bit of how a Minecraft server functions.


If you found these instructions helpful a small donation is appreciated. I will be keeping these instructions up to date with the latest versions of Forge for 1.12.2.


Copyright © 2024 Al Audet