Thanks for testing. I have managed to get it working. I have mapped /data to /mnt/disk1/minio to prevent it from erasing anything else on the disk. Seems to work just fine.
I have one disk right now, and when I have two disks, I will try to get that working as well. I have read about the {1..4} way of mapping it, so I will give that a try then. Unfortunately I will have to rebuild the data, but that's no disaster since I am using it for a remote Synology NAS backup right now. I will post updates when the time comes with news.