Minecraft

I guess nobody needs an introduction to Minecraft.

Running a vanilla Minecraft server is surprisingly easy. Pretty much everything you need is a relatively modern Java Runtime Environment.

Installation

1. Install Java, so you can run the java -h command on your command line.
2. Go to Minecraft's official server download website
3. Create the directory where you want your Minecraft server to live in. This will be referred to as $GAME_DIR.
4. Copy the server.jar into $GAME_DIR.

Start the Server

Before you can actually use or configure the server, you need to start it once. This initializes some crucial files, such as the eula.txt and the server configuration file server.properties.

To start the server, go into $GAME_DIR and run this command:

java -Xmx1024M -Xms1024M -jar server.jar nogui

Explanation of parameters:

• -Xmx This is the maximum amount of RAM your Minecraft server is allowed to use. For a normal vanilla world 1GB (1024M) should be enough. If you're running into problems, try increasing it, but there's no need to always increase this value.
• -Xms This is the amount of allocated RAM the Server starts with and the minimum of RAM the Server will allocate. It's recommended to set this to the same value as Xmx. This results in the Server ALWAYS using a fix amount of RAM, but also might speed up your server.
• server.jar This is the server file you previously downloaded.
• nogui Since this will most likely run on headless server, you have to specify nogui. The server will otherwise try to open a graphical user interface.

To be able to run the server, you need to accept the end-user license agreement. To do so, open the generated eula.txt. It should look something like this:

#By changing the setting below to TRUE you ...
#Fri Jul 10 15:22:48 CEST 2020
eula=false

To accept to their terms, update the eula value in this file to eula=true.

When running the command again, the server should now start up and create a new world.

Server Configuration

Minecraft offers a configuration file named server.properties.

A detailed description on every option can be found on the minecraft wiki.

However, the most important variables for setting up the server will be cover over here as well.

Operational

• server-ip Leave blank, if you want to serve your server on all interfaces. If you want to only serve from specific interface, specify the IP of that interface.
• server-port The port your server accepts connections from. Default is 25565. If you change it to another value than 25565, you'll have to specify the port on the client when adding the server via address.
  This might look something like this: ip_address:port, e.g. 192.168.178.45:25566.
• white-list A white list specifies a list of users that's allowed to connect. ONLY these specified users can connect to the server, if this is set to true. However, administrator (OPs) are always white-listed.
• max-players The maximum amount of concurrent users.
• level-name This is the name of the folder your world will be stored in. Default is world.
• online-mode If set to true the server will query Mojang and only allow users with verified accounts to connect to your server. If you have friends with cracked Minecraft versions, set this to false.
• motd The name of the server that will be shown to your clients.

Gameplay

• level-seed In case you want to play a specific world, enter your seed before starting the server and agreeing to the eula. If you already created a world, either delete the existing world folder (default name is world) or change the level-name parameter.
• gamemode Either a survival, creative, adventure or spectator.
• view-distance The radius of chunks a user can load. Has a direct impact on player's viewing distance.

Whitelisting

If you enabled whitelisting on your server, only whitelisted users will be able to connect. To add a user to your whitelist, start the server and add them via the server cli interface with /whitelist add USERNAME.

You can also enable/disable the whitelist on the live server with /whitelist on/off.

Whenever you add/remove a user to/from the whitelist, the $GAME_DIR/whitelist.json file will be automatically updated.

Server commands

Here are a few useful commands for server operators.

• /time set [day, night] Set the time of the day.
• /forceload add <from> [<to>] force load a chunk. <from> and <to> are a tuple of x and z each.
• /forceload query show all loaded chunks.
• /gamerule playersSleepingPercentage 0.3 The amount of players that need to sleep for the night to be skipped.