Lots of people have mentioned rsynx, restic, borgbackup, and others, but which would be best for backing up nextcloud, immich, and radicale? Do all of them have a method of automatically backing up every X days/weeks? Why use one over the other, what are the differences?
Container databases seem as simple as shutting down a container, running a backup and then starting the container again. Although my my experience is only from hosting a Lemmy/PieFed instance. I did make many backups and restores with no issues to the database. It all worked as I intended it to work.
I would imagine a similar process for non container databases. Stop, backup, restart. Although someone with more experience would be better to answer that.