Minecraft JVM Startup Flags Generator

Generate the optimal Java startup command for your Minecraft server. Choose Aikar's G1GC flags for Paper/Spigot, ZGC for Java 17/21+ servers, or a clean baseline — then copy ready-to-use DustBowl Warden startup parameters, Linux shell scripts, or Windows batch files.

Server Configuration

RAM Allocation 4 GB

Recommended: 4 GB minimum for Paper servers

Java Runtime Version

Configure your container runtime in Warden > Startup

JAR Filename

Server Software

Target OS / Environment

Garbage Collector

Generated Startup Warden Startup Arguments

-XX:+UseG1GC -XX:+ParallelRefProcEnabled -XX:MaxGCPauseMillis=200 -XX:+UnlockExperimentalVMOptions -XX:+DisableExplicitGC -XX:+AlwaysPreTouch -XX:G1NewSizePercent=30 -XX:G1MaxNewSizePercent=40 -XX:G1HeapRegionSize=8M -XX:G1ReservePercent=20 -XX:G1HeapWastePercent=5 -XX:G1MixedGCCountTarget=4 -XX:InitiatingHeapOccupancyPercent=15 -XX:G1MixedGCLiveThresholdPercent=90 -XX:G1RSetUpdatingPauseTimePercent=5 -XX:SurvivorRatio=32 -XX:+PerfDisableSharedMem -XX:MaxTenuringThreshold=1

In your DustBowl Warden Panel, navigate to Startup > Additional JVM Arguments (or Startup Parameters) and paste the flags above.

GC Quick Reference

Aikar's G1GC

Battle-tested for Minecraft. Tuned for large heaps and bursty object allocation. Best for Paper/Spigot with 4–16 GB RAM.

ZGC

Java 17+ concurrent collector with very low pause times. Great for 16+ GB servers. Not officially recommended below 4 GB.

Baseline

No custom GC flags — JVM picks defaults. Good for testing or Forge modpacks that break under G1GC tuning.