You are looking for a disaster recovery plan. I believe you are going down the right path, but it’s something that will take time.
I backup important files to my local NAS or directly store them on the local NAS.
This NAS then backs up to an off site cloud backup provider BackBlaze B2 storage.
Finally, I have a virtual machine that has all the same directories mounted and backs up to a different cloud provider.
It’s not quite 3-2-1… but it works.
I only backup important files. I do not do full system backups for my windows clients. I do technically backup full Linux vms from within Proxmox to my NAS…but that’s because I’m lazy and didn’t write a backup script to back up specific files and such. The idea of being able to pull a full system image quickly from a cloud provider will bite you in the ass.
In theory, when backing up containers, you want to backup the configurations, data, and the databases… but you shouldn’t worry about backing up the container image. That can usually be pulled when necessary. I don’t store any of my docker container data in volumes… I use the folder mapping from host to directory in docker container… so I can just backup directories on the host instead of trying to figure out the best way to backup a randomly named docker volume. This way I know what I’m backing up for sure.
Any questions, just ask!