---
title: "Start File Generator — Spectra"
canonical_url: "https://usespectra.app/tools/start-file"
last_updated: "2026-09-03T14:39:57.523Z"
meta:
  description: "Build the start script for your server: memory, JVM flags, operating system and restart behaviour, ready to drop next to the jar."
  "og:description": "Build the start script for your server: memory, JVM flags, operating system and restart behaviour, ready to drop next to the jar."
  "og:title": "Start File Generator"
  "twitter:description": "Build the start script for your server: memory, JVM flags, operating system and restart behaviour, ready to drop next to the jar."
  "twitter:title": "Start File Generator"
---

# **Start File Generator**

Build the start script for your server: memory, JVM flags, operating system and restart behaviour, ready to drop next to the jar.

Server jar

Memory

GB

JVM flags

Operating system

**Show server GUI**

**Restart automatically**

**Vector API module**

Needs Java 17 or newer and a build that ships incubator modules. Turn it off if the server refuses to start with a module-not-found error.

start.sh

```
#!/bin/bash
while true; do
  java -Xms4096M -Xmx4096M --add-modules=jdk.incubator.vector -XX:+UseG1GC -XX:+ParallelRefProcEnabled -XX:MaxGCPauseMillis=200 -XX:+UnlockExperimentalVMOptions -XX:+DisableExplicitGC -XX:+AlwaysPreTouch -XX:G1HeapWastePercent=5 -XX:G1MixedGCCountTarget=4 -XX:G1MixedGCLiveThresholdPercent=90 -XX:G1RSetUpdatingPauseTimePercent=5 -XX:SurvivorRatio=32 -XX:+PerfDisableSharedMem -XX:MaxTenuringThreshold=1 -Dusing.aikars.flags=https://mcflags.emc.gs -Daikars.new.flags=true -XX:G1NewSizePercent=30 -XX:G1MaxNewSizePercent=40 -XX:G1HeapRegionSize=8M -XX:G1ReservePercent=20 -XX:InitiatingHeapOccupancyPercent=15 -jar server.jar --nogui
  echo "Server stopped. Restarting in 5 seconds — press Ctrl+C to cancel."
  sleep 5
done
```

Heap

4 GB

Flags

21

File

start.sh

## **Features**

### **Flags that are actually used**

Aikar's set is the tuning most Paper servers run, taken verbatim — including the two G1 variants that differ by heap size, not just by a number in -Xmx.

### **Memory estimate**

Two sliders, players and mods, give a starting figure. Mods weigh more than players because their cost is fixed regardless of how many people are online.

### **Ready to run**

The script comes out complete for the chosen system — a batch loop on Windows, a while loop on Linux — with the download named correctly.

## **Frequently asked questions**

## **Come say hi**

Support, mod recommendations, build feedback and weekend events. The Discord is where Spectra actually lives.

**50+**

members

[Join the Discord](https://discord.gg/pv52eNr6uc)