Server Backup Script Generator

Configure automated Linux backup routines with concurrency flock locks, RCON memory-to-disk flushing, SHA-256 integrity checks, age and count-based pruning, systemd timers, and crontab automation.

BACKUP ENGINE

Backup Target Overview

Target Engine Minecraft

Compression Format TarGz

Retention Policy 14 Days (Max 30)

Schedule Cadence Daily

Parameters

Game Engine

Server Identifier

Source Save Directory

Destination Archive Directory

Archive Format

Keep Days

Max Archives

Enable RCON Memory Flush

RCON Port

Password Env

Schedule Cadence

Save to /opt/dustbowl/scripts/backup_mc_survival.sh (chmod +x)

#!/usr/bin/env bash
set -euo pipefail

# =============================================================================
# DustBowl GameTools - Automated Game Server Backup & Pruning Script
# Server Name:   mc_survival
# Game Engine:   Minecraft
# Source Path:   /home/steam/minecraft/world
# Backup Target: /home/steam/backups/minecraft
# Retention:     14 days (Max 30 archives)
# =============================================================================

TIMESTAMP=$(date +%Y%m%d_%H%M%S)
SOURCE_DIR="/home/steam/minecraft/world"
BACKUP_DIR="/home/steam/backups/minecraft"
ARCHIVE_NAME="mc_survival_${TIMESTAMP}.tar.gz"
ARCHIVE_PATH="${BACKUP_DIR}/${ARCHIVE_NAME}"
LOCKFILE="/tmp/backup_mc_survival.lock"

# 1. Concurrency lock protection
exec 200>"$LOCKFILE"
flock -n 200 || { echo "[$(date -u)] Backup already running. Aborting."; exit 1; }

mkdir -p "$BACKUP_DIR"

# 2. RCON safe flush & freeze before snapshot
echo "[$(date -u)] Flushing game state to disk via RCON..."
mcrcon -H "127.0.0.1" -P 25575 -p "${RCON_PASSWORD:-}" "save-off" "save-all flush" || true
sleep 2

# 3. Create compressed archive
echo "[$(date -u)] Creating backup archive: $ARCHIVE_NAME..."
tar -czvf "$ARCHIVE_PATH" -C "$(dirname "$SOURCE_DIR")" "$(basename "$SOURCE_DIR")"

# 4. Thaw world saving after snapshot
mcrcon -H "127.0.0.1" -P 25575 -p "${RCON_PASSWORD:-}" "save-on" || true

# 5. Generate SHA-256 checksum verification
sha256sum "$ARCHIVE_PATH" > "${ARCHIVE_PATH}.sha256"

# 6. Prune old backups exceeding retention limits
echo "[$(date -u)] Pruning backups older than 14 days in $BACKUP_DIR..."
find "$BACKUP_DIR" -maxdepth 1 -type f -name "mc_survival_*.tar.gz*" -mtime +14 -delete || true

# Enforce maximum backup count limit (30)
COUNT=$(find "$BACKUP_DIR" -maxdepth 1 -type f -name "mc_survival_*.tar.gz" | wc -l)
if [ "$COUNT" -gt 30 ]; then
  EXCESS=$((COUNT - 30))
  echo "[$(date -u)] Removing $EXCESS excess archive(s)..."
  find "$BACKUP_DIR" -maxdepth 1 -type f -name "mc_survival_*.tar.gz" -printf '%T@ %p\n' | sort -n | head -n "$EXCESS" | awk '{print $2}' | while read -r OLD_FILE; do
    rm -f "$OLD_FILE" "${OLD_FILE}.sha256"
  done
fi

echo "[$(date -u)] Backup successfully completed."