While the crew had interesting backup strategies, I think mine is worth sharing.
First is I do a home hosted sync software (on a Raspberry pi with a connected USB hard drive) which my wife and my smart phone and computers sync common stuff to. Like photos and videos, Joplin note files, and a folder called Dropbox but we don’t actually use Dropbox.
For backup we use Restic (https://restic.net/) - I learned about it on Front Page Linux and really liked its simplicity in usage but also power underneath.
So here is how it works for me:
Restic runs via cronjob on the pi every hour and takes a snapshot of what’s on the external drive.
Restic also runs every hour on all our computers in the house, syncing folders that aren’t already synced to the raspberry pi every hour. We tell restic to keep data for 7 - 30 days.
I signed up for Digital ocean and create a space for each computer. Restic uses a password for encrypting the data - each computer has its own key to the DO spaces and their own Restic password. This way if a computer is ever lost or compromised - the key for access to the DO space can be deleted ASAP, then the data can be recovered and then the space containing the compromised/lost computers backup can be deleted.
I know I don’t have 3 copies of everything, so I’m working on creating a script to sync the backups to DO space in a different region. This way the data is stored in 3 different locations at a minimum.
I have thought about hosting hard drives at a relatives house, but I am not keen on figuring out VPN / firewalls between houses. I prefer just having DO spaces in multiple regions that I control and the data is encrypted before leaving the computers.
Some might be wondering about cost. DO space is the most expensive part. But it’s only $12/month to host a copy of the backup for everything on all my computers. I presume when I replicate the data to another DO space - the cost will double to $24/month.