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Minecraft (Java) Server in Docker on a Synology NAS

Please note if you are using DSM7.2 or higher you should use the Container Manager version of this guide from the menu.
UpdateDate
Added a note in relation to enabling the RCON port and if you expose it to the internet you MUST change the default password.22/04/2023
Historic updates now at the end of the guide.

In this guide I am going to take you through the steps to get a Minecraft JAVA server up and running in Docker on a Synology NAS. If you are looking to host a server for a Console or Mobile you will want to see my Bedrock edition guide.

The fantastic documentation on how to use the server once it is running can be found here

https://docker-minecraft-server.readthedocs.io/en/latest/

Let’s Begin

In order for you to successfully use this guide please complete the setting up a docker user guide, or have your ID details to hand.

Step 2: Setting up a restricted Docker user
Step 3: Setting Up a Docker Bridge Network

Downloading the Container

Open up Docker within DSM and navigate to the ‘Registry’ tab and search for ITZG in the keyword box.

Within the results right click and download the ‘ITZG|Minecraft-Server’, When it asks which version number to download select the one that you require based on the table below

Minecraft VersionTag to Select
v1.18x and upLatest or JAVA17
v1.17xJAVA16
v1.16 and belowJAVA15

Setting up the container

Now we have downloaded the container and got hold of our user IDs we can move onto the next stage.

Go back into Docker and click on the ‘Image’ tab, in the list of your containers select the ITZG Minecraft server, and click on ‘Launch’

You will be greeted with the Network screen, we will be using the ‘synobridge’ network we created earlier select it from the list and click Next.

Next you will be greeted with the General Settings screen, this is where you can start specifying some of your preferences.

Minecraft can be fairly CPU heavy so if you are running the server on a lower specification Synology box you will probably want to set limits around the CPU priority or Memory Limit. This will ensure DSM is still usable when the server is running.

You can change the name of the container to anything you like, and you may want to enable Auto Restart as this will ensure the server starts automatically if you reboot your NAS.

Next up we are going to click on the ‘Advanced Settings’ button, this will take you to a new window with a number of tabs which we are going to work through.

Environment Variables – GID, UID, Server Type and EULA

We are now going to set up the specific options for the server including what type of server you would like to run and even a specific version.

Each of the values below are added by clicking the ‘Add’ button at the top of the screen and then entering each of the values below

Please note if you decide to enable the RCON Port please change the default password especially if you open your server up to the Internet! See the GitHub for more details.

variableValueComment
UIDThis will be prefilled with 1000 change it to the UID you obtained earlier
GIDThis will be prefilled with 1000 change it to the GID you obtained earlier
EULATRUEThis accepts the Minecraft EULA, without this the server will not run
TYPESPIGOTYou can change this as per the list below
VERSIONLATESTYou can change this to any a specific version if you want e.g 1.13
JVM_XX_OPTS-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 -XX:G1NewSizePercent=30 -XX:G1MaxNewSizePercent=40 -XX:G1HeapRegionSize=8M -XX:G1ReservePercent=20 -XX:InitiatingHeapOccupancyPercent=15These variables are used to increase the performance of the server – Copy and paste this exactly
MAX_MEMORY2GAmend the number to the amount of memory you want to allocate to the server this will depend on your system or server type you are running

Server Types

  • VANILLA
  • BUKKIT
  • SPIGOT
  • PAPER
  • TUINITY
  • MAGMA
  • MOHIST
  • CATSERVER
  • SPONGEVANILLA
  • FABRIC

See the full list here

You do not need to set up anything on these tabs.

Press ‘Save’ to go back to the initial setup screen, then press ‘Next’

Port Settings

You will now see the Port Settings screen. You will need to type in the ‘Local Port’ to match the ‘Container Port’ shown on the right-hand side this will avoid the container being assigned random ports when it is started. When set press Next.

As per the earlier note if you decide to enable RCON you will need to add its port mapping here.

Volume Settings

We can now specify the directory where Minecraft will store its configuration files.

Click on Add Folder, click on the docker folder and create a new sub-folder called ‘minecraft’ select this folder and click ‘select’

Now we need to specify where this folder will be mounted inside the container. As per the screenshot/table below, enter /data into the ‘Mount path’.

File/FolderMount path
docker/minecraft/data

Click on Next and you will be taken to an overall summary screen, just do a quick sanity check to make sure the options are correct. If you want to launch the server immediately check the box and click on Done.

Server startup time

The first time the server launches it may take a few minutes for the server files to download and the world to be generated. You can track the progress by going into the ‘Containers’ tab and clicking on details for the Minecraft container, then either viewing the terminal or log tabs.

All other server settings can be configured using the standard Minecraft server.properties file, I won’t be covering that here as there are extensive other guides out there.


Update HistoryDate
Added Docker Compose details03/05/2021
Updated to show which version of the image to download09/06/2021
Cleaned up the Environment Variables section and included some new JAVA optimisations24/11/2021
Screenshots update to DSM7 and tweaked the guide wording22/01/2022
DSM7.1 Update with new screenshots and steps24/05/2022
Added new port settings and Docker Bridge Network23/07/2022
Fixed the missing port settings section!16/11/2022
Removed port 25575 (RCON) as could pose a security issue if exposed to the internet – You can add manually if required12/03/2023
Compose version number removed 3.x not required, and some minor wording amendments.08/04/2023
Amended the path to save the compose file – this is for security, so the container has no access to the file contents.14/04/2023
Update History

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Published inGaming 7.1

109 Comments

  1. Missing a minecraft/ in the docker-compose command I think

    sudo docker-compose -f /volume1/docker/minecraft.yml up -d

    should be

    sudo docker-compose -f /volume1/docker/minecraft/minecraft.yml up -d

    • Also, if you plan on running Geyser to get Bedrock clients able to connect you must forward udp to port 19132:

      - 19132:19132/udp

      I didn’t realize docker wouldn’t send tcp & udp by default, should’ve known

      • thank you 🙂 I’ve been loving these guides, saved me a lot of doc reading (and left enough info in to help me understand what’s going on), so I’m gratified to help you!

  2. Ant Ant

    Hello, I have no problems running the server with the above tutorial. However, when I change the Type to Curseforge, it fails to run. I looked over the ITZG Github page & have tried adding different environment variables like CF_PAGE_URL, CF_SLUG but no luck.

    Any suggestions?

  3. Jesper Jesper

    Great tutorial. Bought you coffee! Server is running. I can connect via local ip. What do I tell friends to let them connect? Which IP? Is synologyh quickconnect in play here? mystaticIP:portnumber? thanks.

    • Dr_Frankenstein Dr_Frankenstein

      Hey thanks for the coffee!

      So you can forward port 25565 on your router to your NAS IP and then your friends can connect via your quickconnect / DDNS address 🙂

  4. Noobhoch12 Noobhoch12

    Really good tutorial but the problem I have I can join the server but my friends cannot join it did I do something wrong or it’s not working?

    Thanks

    • Dr_Frankenstein Dr_Frankenstein

      Hey – I will get the guide updated with how to also have a reverse proxy address for the server as well.

      If you check out the Overseerr guide in the interim and follow the section called ‘Part 2 – DDNS, SSL and Reverse Proxy’ and when choosing a proxy name use minecraft.yourDDNSname.me and use port 25565 instead of 5055.

      • Noobhoch12 Noobhoch12

        can u explain it a little bit more detailed because if I have made it right what you have explained it still not working

        Thanks : )

        • Dr_Frankenstein Dr_Frankenstein

          Can you reach out via my contact page or Discord (top option on the menu) it will be easier than via the comments.

  5. TrDy73 TrDy73

    I’ve followed this guid 100%, but I’m unable to connect to the server at all. It starts up and i can see in the console that the server is running like it should. Any suggestions?

    • Dr_Frankenstein Dr_Frankenstein

      Hey, I am not sure how but the step in the guide that directs which ports to assign seems to have vanished!

      Edit the container and in the Port Settings make sure you change the Local Ports to 25565 and 25575, so they line up with the Container Ports.

      That would be my initial guess, I will get the guide fixed ASAP!

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