If you want to install a modpack that isn’t listed on in our JAR Installer, you can do so manually via FTP. The first thing you will need to do is decide what pack you want to be installed. You can select from a variety of modpacks on the Technic, FTB, or ATL site.
This guide assumes you will be working with a modpack that has prepared a server version for you. Not all modpacks will provide one. If this is the case you will need to convert the client version into a server version.
Prepping The Pack
Once the download has completed we need to prep the modpack for installation onto the server. So navigate to where it was downloaded and extract the contents of the compressed file into a folder which will refer to as temp.
Then we should run the pack to give it the chance to download any missing files. Running it locally also gives you the chances to test out and ensure it’s working before taking the step to install it on the server. To start the server up, launch the .bat (start.bat) for Windows users or .sh (start.sh) file for Linux users.
If successfully initialized you will see the “Startup Done” message in the console.
Next, we should clean up any unnecessary files. Since we tested the pack locally and confirmed it worked, we can delete all pretty much everything that wasn’t originally contained in the extracted pack along with the execution files, the .bat, and .sh files.
With our final step in preparation, we now need to set up the jar files in the manner the panel reads from which is from within the “jar” folder. Create a new folder in temp and label it “jar”.
The jar files consist of 3 items, the base jar for running the Minecraft server, the forge jar that’s used to run forge, and the libraries folder containing the necessary components to run the forge jar. Take these files and move them into the jar folder.
Then rename the forge jar to “custom256.jar”.
We can now upload our files to our server using a third party FTP client such as Filezilla. To upload we simply drag and drop all the server files into the server’s home directory and wait for it to finish uploading.
Configuring The Server To Run The Pack
Once the upload is complete, we’re pretty much good to go. The final thing we need to do is tell the server what jar it should be looking for in order to run which would be the forge jar.
Now in step 6, we renamed our forge jar to custom256.jar. The important thing to note is that the 256 stands for the amount a perm gen in megabytes assigned to the server on start. This feature is quite useful for most modpacks as it gives a little more RAM on startup to get it going.
With that renamed we now need to tell the server to look for that particular jar. To do this we head back to the servers details page and locate the jar entry field and enter in the name of the forge jar; custom256.jar and then save.
Next, we can start the server and review it initialization by heading over to the console. The initialization process should only take a minute or two with a continuous output until you see the startup done message or the check mark indicating the server has successfully started up. After that, you can then connect to your server with the respective client.