Installing the Minecraft server
Once you have a machine that meets the minimum Minecraft server requirements, it is now time to install the Minecraft server on Ubuntu. Start by opening up the terminal. The terminal can be located in the applications menu under accessories.
Once the terminal is open, you will be greeted with a command prompt. Create a new directory for the server software by typing in the following command:
user@mineserv:~$ mkdir minecraft-server
Now, change directories to the newly created directory by typing
user@mineserv:~$ cd minecraft-server/
Once you're in the newly created directory, its time to download the Minecraft server software. This can be done using the wget command, shown below.
user@mineserv:~$ wget -O minecraft_server.jar http://minecraft.net/download/minecraft_server.jar
Once this command finishes executing, you will have successfully downloaded the Minecraft server software. In order to run it, you need to execute the following command:
user@mineserv:~$ java -Xmx1024M -Xms1024M -jar minecraft_server.jar nogui
If everything went well, you will be greeted with the following message after the server finishes setting up:
[INFO] Done! For help, type "help" or "?"
Make sure to keep this terminal window open in order to continue running the server, as closing it will cause the server software to close.