Imported from Nattapat2871/raphael-skills (codex-skills/minecraft-server-admin/SKILL.md). Install upstream with npx skills add Nattapat2871/raphael-skills --skill minecraft-server-admin. Copyright stays with the author.

Minecraft Server Administration Skill

Scope and Routing Boundaries

Routing Boundaries

• Use when: the task is infrastructure or live operations for Minecraft servers (deployment choice, tuning, backups, proxying, security, incident response).
• Do not use when: the task is writing plugin code (minecraft-plugin-dev) or writing mods/loaders (minecraft-modding, minecraft-multiloader).
• Do not use when: the task is WorldEdit command workflows (minecraft-worldedit-ops) or EssentialsX workflow/policy design (minecraft-essentials-ops).
• Do not use when: the task is datapack/resource-pack authoring (minecraft-datapack, minecraft-resource-pack).

Support Assets

• Read references/deployment-checklists.md when the task is an incident, rollout window, proxy change, or recovery drill and you need a compact checklist before acting.

Deployment Decision Matrix

Use this table first. Pick a deployment type before changing configs.

Deployment Type Routing

• Small SMP and most public plugin servers: use Paper baseline first.
• Use Purpur only when you explicitly need Purpur gameplay controls.
• Use Folia only when plugin compatibility has been validated for region-threading.
• Use Velocity when one process is not enough or you need separate backend roles.
• Use Fabric/NeoForge when the requirement is mod-driven, not plugin-driven.

Playbook: Performance Tuning

Step 1: Establish baseline

Collect a baseline before edits. Linux host example:

free -h
top -b -n 1 | head -n 25

Windows PowerShell host example:

Get-CimInstance Win32_OperatingSystem | Select-Object FreePhysicalMemory,TotalVisibleMemorySize
Get-Process java | Sort-Object CPU -Descending | Select-Object -First 5 Id,CPU,WorkingSet,Path

In server console:

tps
mspt
spark healthreport

Record:

• peak player count
• MSPT at idle and at peak activity
• top plugins by CPU from Spark report

Step 2: Profile the real bottleneck

Use Spark instead of guesswork:

spark profiler --timeout 180
spark tps
spark tickmonitor --interval 10

Then identify whether the issue is:

• plugin task load
• entity count / mob farm pressure
• chunk generation / disk I/O
• garbage-collection pauses

Step 3: Apply targeted fixes

Do not tune everything at once. Apply one group at a time.

1. Chunk and simulation pressure:

• lower view-distance and simulation-distance first
• pre-generate worlds for survival-heavy maps

1. Entity pressure:

• adjust despawn ranges and mob-spawn behavior in Paper world config
• cap problematic entities where appropriate

1. Plugin pressure:

• disable or replace top offenders from Spark traces
• reduce async task frequency where plugin settings allow

Step 4: Use stable startup flags

For Java 21 on Paper/Purpur:

java -Xms10G -Xmx10G \
  -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 \
  -Dfile.encoding=UTF-8 \
  -jar server.jar --nogui

For under 12 GB memory budgets, reduce heap and use smaller region size.

Step 5: Verify improvements

After each change set:

spark tps
spark healthreport

Keep the change only if MSPT/tick stability improves under representative load.

Playbook: Plugin Operations

Safe plugin change workflow

1. Build a plugin inventory:

• plugin name and version
• required dependencies
• minimum server version

1. Stage updates:

• apply plugin updates in staging first
• run smoke checks: joins, teleports, economy, permissions, saves

1. Production rollout window:

• announce maintenance window
• stop server cleanly
• snapshot plugin jars and config
• deploy update batch

1. Post-rollout verification:

• watch startup logs for API warnings
• run command and permission sanity checks
• track TPS/MSPT for 15-30 minutes

Rollback checklist

• Keep previous plugin directory snapshot.
• If severe regression occurs:
  • stop server
  • restore prior plugin jars/configs
  • start and confirm login/world integrity
• Document failing plugin/version pair for future blocks.

Playbook: Proxy and Forwarding (Velocity)

Velocity baseline

velocity.toml essentials:

bind = "0.0.0.0:25565"
online-mode = true
player-info-forwarding-mode = "modern"
forwarding-secret-file = "forwarding.secret"

Backend server requirements

server.properties on backend:

online-mode=false

Paper backend forwarding support (config/paper-global.yml):

proxies:
  velocity:
    enabled: true
    online-mode: true
    secret: "paste-the-shared-forwarding-secret-here"

Use the same secret value stored in Velocity's forwarding.secret file; the backend config takes the secret string itself, not a file path.

Keep enforce-secure-profile at the server default unless you are handling a specific legacy-client or incident workaround. It is not part of the baseline Velocity setup. Also confirm settings.bungeecord: false in spigot.yml; do not enable BungeeCord forwarding and Velocity modern forwarding at the same time.

Validation runbook

1. Confirm proxy port is reachable from clients.
2. Confirm backend is firewalled from direct internet access.
3. Join through proxy and verify:

• UUID consistency
• skin/profile forwarding
• plugin permission behavior

Common proxy incidents

• "Invalid player info forwarding":
  • mismatch in forwarding mode or shared secret between Velocity and backend.
• Random auth/session failures:
  • mixed online-mode expectations or direct backend exposure.

Playbook: Backup and Recovery

Backup policy template

Example backup script

For a production server, quiesce world writes before copying live world folders. The example below assumes a maintenance window and a cleanly stopped server. If you use RCON-based live backups instead, choose a client/secret mechanism that does not expose the password in command arguments, flush chunks first, and test the restore path before trusting the backup.

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

: "${SERVER_STOPPED_CONFIRMED:?set SERVER_STOPPED_CONFIRMED=1 after stopping the server cleanly}"

DATE="$(date +%Y-%m-%d_%H-%M-%S)"
BACKUP_ROOT="/backups/minecraft"
SERVER_ROOT="/srv/minecraft"
DEST="${BACKUP_ROOT}/${DATE}"

mkdir -p "$DEST"

tar -czf "${DEST}/worlds.tar.gz" -C "$SERVER_ROOT" world world_nether world_the_end

state_items=()
for item in \
  plugins config server.properties bukkit.yml spigot.yml paper-global.yml \
  paper-world-defaults.yml permissions.yml ops.json whitelist.json \
  banned-players.json banned-ips.json; do
  [[ -e "$SERVER_ROOT/$item" ]] && state_items+=("$item")
done

if [[ "${#state_items[@]}" -gt 0 ]]; then
  tar -czf "${DEST}/server-state.tar.gz" -C "$SERVER_ROOT" "${state_items[@]}"
fi

Recovery drill (must be tested)

1. Stop server.
2. Restore selected backup to staging directory.
3. Validate ownership/permissions.
4. Start server in maintenance mode.
5. Verify:

• world spawn loads
• player data is readable
• key plugins initialize

1. Reopen to players.

Define targets:

• RPO (acceptable data loss window)
• RTO (acceptable restore duration)

Playbook: Live Troubleshooting

Incident triage flow

1. Classify incident:

• crash on startup
• severe lag / TPS collapse
• join/auth failures
• memory/disk pressure

1. Capture evidence first. Linux host example:

df -h
free -h

Windows PowerShell host example:

Get-PSDrive -PSProvider FileSystem
Get-CimInstance Win32_OperatingSystem | Select-Object FreePhysicalMemory,TotalVisibleMemorySize

From server/proxy console:

spark tps
spark healthreport

1. Stabilize:

• stop risky rollout changes
• disable newest suspect plugin first
• reduce player impact (maintenance mode, temporary queue, restricted worlds)

1. Recover and document:

• apply rollback or hotfix
• document root cause and permanent preventive action

Fast symptom map

Operational Config Reference

server.properties high-impact keys

max-players=100
view-distance=10
simulation-distance=8
sync-chunk-writes=true
max-tick-time=60000
enable-rcon=false

bukkit.yml and spigot.yml

Use Spigot/Bukkit docs as authoritative for version-specific defaults and side effects. Tune conservatively and re-measure after every change set.

Paper config files

• config/paper-global.yml
• config/paper-world-defaults.yml

Adjust these only after profiling identifies an actionable bottleneck.

Deployment Patterns

Docker Compose (Paper)

services:
  paper:
    image: itzg/minecraft-server:java21
    container_name: mc-paper
    environment:
      EULA: "TRUE"
      TYPE: "PAPER"
      VERSION: "1.21.11"
      MEMORY: "10G"
    ports:
      - "25565:25565"
    volumes:
      - ./data:/data
    restart: unless-stopped

This Docker example targets the repository's 1.21.x guidance and Java 21. Minecraft 26.1.x/Paper 26.x requires Java 25 and Paper's 26.x version line; use a Java 25 image and re-check plugin compatibility before changing VERSION.

Pterodactyl/Wings notes

• Keep startup command and memory allocations consistent with tested JVM flags.
• Pin panel and Wings versions to supported combinations.
• Validate backup mount and restore workflow before production.

Security Hardening Checklist

• Keep online-mode=true unless proxy forwarding requires backend online-mode=false.
• Never expose backend Paper ports directly when using Velocity.
• Restrict RCON and panel/admin surfaces by firewall/IP allowlist.
• Rotate secrets (forwarding.secret, panel credentials, backup credentials).
• Keep plugin sources trusted; verify checksum/release source before install.
• Maintain off-host encrypted backups.
• Keep Java runtime and host OS patched.

References

Paper (primary)

• https://docs.papermc.io/paper/
• https://docs.papermc.io/paper/admin
• https://docs.papermc.io/paper/profiling/

Spigot/Bukkit (primary config reference)

• https://www.spigotmc.org/wiki/spigot-configuration/
• https://www.spigotmc.org/wiki/bukkit-configuration/
• https://www.spigotmc.org/wiki/start-up-parameters/

Proxy and ecosystem docs

• https://docs.papermc.io/velocity/
• https://spark.lucko.me/docs
• https://geysermc.org/wiki/geyser/
• https://pterodactyl.io/project/introduction.html