Startup parameters: how your game server starts

The Startup tab is under Setup on your game server. The owner can change it, and anyone who was given the Setup right when it was shared.

The start command

At the top is the Start command as it will run at the next start, with every value filled in. Passwords in it (a server or RCON password, for example) appear as dots; Show password reveals them. A long line is shortened; Show all shows the whole of it.

Changing values

• Every value has its own card with its name and the technical key below it. Depending on the value it is a switch, a choice or a text field.
• A text field is saved when you leave it or press Enter; a check mark shows it is saved. Switches and choices save at once.
• Values with a lock cannot be changed in your plan, but you can see them.
• Rarely needed values, such as paths or Steam IDs, are folded away under Technical values.
• Every change is listed in the server's Activity.

Runtime and Java version

If your game has more than one environment, choose it under Runtime. For Minecraft this is the Java version: new game versions often need a newer one. If you chose your own Java setting below, it is rewritten for the new version when you switch. More under Java version.

Java setting

If your server starts Java itself, as Minecraft does, the Java card appears. It says how much of the memory Java gets for the game; the rest stays for Java itself, so the server is not stopped for lack of memory under load.

Standard

What the game image sets, with enough room for Java beside the game. Runs everywhere.

Optimised (G1)

Aikar's proven settings for current Java: shorter pauses while memory is cleaned up, good up to about 12 GB.

Large server (ZGC)

Pauses under a millisecond even with a lot of memory. Needs Java 21 or newer and at least 8 GB.

• Recommended for this server is shown under the choice we would make for your server: ZGC from 12 GB where possible, otherwise G1.
• Under Additional flags (optional) you add up to 20 flags of your own, only -D… properties and -XX:… options. Flags for memory and flags that run commands are refused: the memory is set by the setting above.
• Save applies it, effective at the next start.
• If the start command or the file user_jvm_args.txt sets how much Java gets, the card says so. If that leaves Java hardly any room, a warning appears.

Minecraft: server file and version

• You pick the Server file from the .jar files in the main folder. If the file entered is not there, the card says so, because the server will not start like that.
• Since Minecraft 1.17, Forge and NeoForge start through an argument file; there is no server file then.
• Below the version values you see what is installed. If a reinstall would take a different version, Match sets the value to the installed one.
• Software and version are easier to switch in the Version tab: Switch software and version.