Startup settings, Java flags and memory

What is the Startup tab, and should I change the Java flags?

Startup shows the command and variables used to launch the server; the defaults are tuned already, and the memory is set from your plan.

Before you start: A note of the current values so you can put them back.

Step by step

1. Open Startup to see the startup command and variables such as the server jar name.
2. Leave memory alone: the plan's memory is applied automatically. Setting -Xmx above your plan gets the server killed (exit code 137).
3. If you run a custom jar, set the jar file variable to its exact file name in the root folder.
4. Aikar's flags (G1GC tuning) help Paper servers with 6 GB or more; add them only if the startup command does not already include them.
5. Save and restart after any change, and watch the console for "Unrecognized option" errors, which mean a typo in a flag.

Check it worked: The server starts cleanly with the new settings.

Why it happens: Wrong flags or more memory than the plan allows make the server crash or get killed.

More guides on Control panel and server setup:

• Start your server for the first time
• Power buttons, and a server stuck starting
• Change the server software or Minecraft version
• Change the MOTD, max players, difficulty, gamemode or PvP
• Generate a new world or set a seed
• Edit server.properties and other configs