Please note if you are using DSM7.2 or higher you should use the Container Manager version of this guide from the menu.
This guide has reached the end of its updates as most people are now on the latest DSM update - This guide is correct as of 08/12/2023 however no further updates will be added.
| Update | Date |
|---|---|
| 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 |
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 Version | Tag to Select |
| v1.18x and up | Latest or JAVA17 |
| v1.17x | JAVA16 |
| v1.16 and below | JAVA15 |
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.
| variable | Value | Comment |
| UID | This will be prefilled with 1000 change it to the UID you obtained earlier | |
| GID | This will be prefilled with 1000 change it to the GID you obtained earlier | |
| EULA | TRUE | This accepts the Minecraft EULA, without this the server will not run |
| TYPE | SPIGOT | You can change this as per the list below |
| VERSION | LATEST | You 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=15 | These variables are used to increase the performance of the server – Copy and paste this exactly |
| MAX_MEMORY | 2G | Amend 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
Links / Execution Command
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/Folder | Mount 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 History | Date |
| Added Docker Compose details | 03/05/2021 |
| Updated to show which version of the image to download | 09/06/2021 |
| Cleaned up the Environment Variables section and included some new JAVA optimisations | 24/11/2021 |
| Screenshots update to DSM7 and tweaked the guide wording | 22/01/2022 |
| DSM7.1 Update with new screenshots and steps | 24/05/2022 |
| Added new port settings and Docker Bridge Network | 23/07/2022 |
| 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 required | 12/03/2023 |
| 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 |
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Hi,
Thanks for this brilliant guide. I set it all up and worked perfectly as bedrock. Did this so my kids would have a super safe closed environment for them and their friends, all good.
After months of stability suddenly we can’t access the “world” via the Mine craft app as the server is reported as out of date. In settings it should be latest but it’s failing to update with the message in the log file “ minecraft download page failed”.
Any advice on how to sort this?
Thanks.
Hi
Nice guide, especially the part with the restricted user policy. Can I use this methodology also when I set up other docker containers?
Cheers
Hey, all the Linux server containers have the UID values, you often need to check the read me to see what the container requires or how it expects permissions to be set.
Hello,
I followed this guide and was able to startup a Minecraft server with no problems. I am now looking at trying to add Forge Mod so I can add Mods to my server but I am not sure what the steps are to install forge. I have downloaded the .jar file forge-1.17.1-37.0.126-installer.jar but am not sure how to install this on the server. Is this possible within the container I have created using your steps or do we have to create an entire new container with this forge package and if so are you able to provide the steps on how to do that?
Thanks,
Cody
Hey, you can change the server type with the ‘Type’ environment variable to CURSEFORGE.. I assume you can then put the mods in the MOD folder that is created in the folder you mapped.
Below is the log file after only changing the Type from VANILLA to CURSEFORGE if that helps.
[init] Resolved version given LATEST into 1.17.1
[init] Resolving type given CURSEFORGE
[init] **********************************************************************
[init] NOTE: Some mods and modpacks may require Java 8.
[init] If so, use itzg/minecraft-server:java8
[init] **********************************************************************
[init] Looking for Feed-The-Beast / CurseForge server modpack.
[init] ERROR: FTB_SERVER_MOD is required to be set
Try stopping the container deleting everything inside the /docker/minecraft folder and starting it up again.
I tried this and it wont create anything within the folder now. Log stops and gives the following error at the bottom of the log and then tries to restart again over and over giving the same error.
ERROR: FTB_SERVER_MOD is required to be set
It not installing the Forge mod for me. From what I can find online this needs to be installed and then the environment value can point to the mod. Is this true or are you saying this should just create and install everything and work, if that is the case then its not working like that.
Yes – that is correct https://github.com/itzg/docker-minecraft-server#running-a-server-with-a-curseforge-modpack you need to download the modpack – follow the instructions as per ITZGs instructions – I am making a note on the guide.
I was actually able to get it working by changing the type from CURSEFORGE to FORGE. It downloaded and installed it all for me then. Thanks for your help.
Thank you so much for this! Everything went swimmingly until I try and connect to it from inside Minecraft and it can’t find it…
Have you manually added the server as the built in automatic search never seems to find anything
I have yeah, tried with and without the port. It seems like it finds something, moves to “encrypting” and then says it can’t connect!
Are you using the Java version of minecraft or the Bedrock version?
Java, running on a Mac
When you add the server it should only need the IP of your NAS without the port number.. when you add it does it show up like this?
I can’t connect to it at all now, so no it just says it failed to connect. I seem to be having bigger problems with the container; it’s crashing every 20 or so minutes so I think i might just kill the container and start the process again to see if it was something i did…
It should just show as below – double check the port settings you used
Hi Dr Frankenstein,
Thanks for the terrific guide. I had referred to the Docker repository also, but this is a lot more specific for the Synology deployment. I’m using a 216+II with 8Gb Ram and DSM 7.0.1-42218
I stuffed up the directory settings in Advanced tab prior to running on the first attempt without your notes. I deleted and restarted. Running no problems so far. I intend to use the whilelist.json to admit my sons friends to the server. I’ll update the environment to reflect its use.
I also tried LEVEL_TYPE=AMPLIFIED in environment but I haven’t got it going.
I’ve tested on the LAN side OK, am now to test on the WAN side.
Cheers,