I run something called Nextcloud. It is a ‘personal cloud’ type server with easy app integration for automatic backups. You can run it on a computer at home, or you can run it on a commercial VPS. You can connect as many clients to it as you want, and choose which ones get a copy of what data from the others.

If this sounds like something you might be interested in, I highly recommend you take a look at a project called Yunohost. It is a nice and easy way to get started with hosting your own services. Once it’s up and running, you just install apps (ie, Nextcloud) and it takes care of the configuration for you.