Guide to Minecraft Server Startup Flags

🔧 What Are Startup Flags?

Startup flags are parameters used when launching your Minecraft server to optimize performance and manage resource allocation, such as RAM and CPU usage. These flags are especially important when your server handles many players or mods.

🚀 Types of Flags in Your Panel

In your control panel, you have three options for configuring startup flags:

• Default Flags

• Create a Custom Flag (start.sh)

• Default Flags with a 95% RAM Limit

  
  

Flags por defecto

These are standard configurations recommended for most servers. They use basic memory allocation and JVM setup parameters. If you’re not sure how to adjust your flags, this option is safe for most users.

🚀 Typical Default Flag Command:

java -Xms128M -Xmx8256M -Dterminal.jline=false -Dterminal.ansi=true $( [[ ! -f unix_args.txt ]] && printf %s "-jar server.jar" || printf %s "@unix_args.txt" )

Explanation:

• -Xms128M: The server will use a minimum of 128 MB of RAM.

• -Xmx8256M: The server can use up to a maximum of 8256 MB (8 GB) of RAM.

  
  

Create a Custom Flag (start.sh)

Here, you can manually adjust the flags to maximize performance based on your server’s needs. You’ll need to edit the start.sh file and add the flags you consider necessary.

This is especially useful for servers with high demand, many players, or multiple mods/plugins.

Preconfigured servers likely already have a start.sh file set up and ready to use — you just need to assign permissions (777) so the panel can execute it properly.

🔨 Example of Advanced Flags for Performance Optimization:

java -Xms4G -Xmx8G -XX:+UseG1GC -XX:MaxGCPauseMillis=100 -XX:+UnlockExperimentalVMOptions -XX:+DisableExplicitGC -jar server.jar nogui

Advanced Explanation:

• -Xms4G and -Xmx8G: Allocates between 4 GB and 8 GB of RAM for your server.

• -XX:+UseG1GC: Enables the G1 garbage collector, the most recommended option for Minecraft servers.

• -XX:MaxGCPauseMillis=100: Optimizes garbage collection pauses, keeping them under 100 milliseconds.

• -XX:+UnlockExperimentalVMOptions: Allows experimental Java options for greater performance customization.

• -XX:+DisableExplicitGC: Disables manual garbage collection calls, which can negatively impact performance.

  
  

Default Flags with a 95% RAM Limit

This option limits RAM usage to 95% of the amount allocated to the server, preventing the system from running out of memory. It’s ideal for setups where you want to make sure the server doesn’t consume all available RAM.

🛠️ Typical Command with a 95% RAM Limit:

java -Xms4G -Xmx9.5G -jar server.jar nogui

Explanation:

• -Xms4G: Uses a minimum of 4 GB of RAM.

• -Xmx9.5G: Limits the maximum RAM usage to 95% of the 10 GB assigned to the server.

  
  

💡 Additional Recommendations:

• Monitor RAM usage: If your server experiences high player peaks, consider increasing the maximum RAM limit.

• Test before major changes: If you customize your flags, test performance with a few players before applying it in production.

• Garbage Collector: Using Garbage First (G1GC) is recommended for servers with more than 4 GB of RAM.

That’s it! This guide should help you understand and configure startup flags on your Minecraft server through your panel. If you need help with a specific adjustment or have more questions, I’ll be here to help! 😊

Conclusion

We hope this guide has been helpful! 🚀 Remember, don’t hesitate to ask questions on the HolyHosting Discord or contact our support team.

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Stuffy @ HolyHosting