I have a self-hosted Nextcloud instance running on a laptop in an attic in Europe. I am currently backing the entire instance up (ssh + rsync) to a Raspberry Pi in South America. The entire instance has about 1500 GB of data. Right now I’m reaching on average about 50 MB/minute, which means that it will take two-three weeks to finish. What would be the first steps to take to make this process go faster?