how to help ? I can take the bounty

If you want to store more data, you will need to right click on your canvas, create a volume, and click on your service, and mount it to /data or another mounting point.

Then, in your application, you will need to set the directory where you're saving data to anywhere inside /data. For example, /data/temp.

Thank you for your reply, the thing is the service doesn't store any data. the service is an API in golang.
So I'm not trying to store anything, all files that are being uploaded from the paltform and goign to api are stored in Cloudflare R2, that is the only data storage I do.

But I want know here this coming from and what kind of data is being stored, so I can maybe address this in the codebase or so.

Is ther any way to check this?

I would suggest that you use your API as a proxy and stream the file upload directly to Cloudflare.

One possible reason you might be exceeding the ephemeral storage is that you're attempting to upload the entire file to your API, then your API would forward that entire file at once to R2 instead of streaming. (Though I'm not completely sure as I don't know how your application was built)

There are multiple commands you can run inside the container to check its storage. Right click on your service and copy the SSH command (You need to have railway cli installed). Once you SSH into the container use these commands to analyse the storage.

1. df -h (check overall usage)
2. du -h -d 1 / | sort -hr (find the largest directories)

These two should help you find what's filling up your storage.