Right now I’m creating a nightly restic snapshot of my server on borgbase and on some spare drives, and keeping the snapshots forever. There’s a ton of daily churn in my data though, between databases and logs and other files that don’t constitute ‘real data’ but might be needed to restore the app.
I backup once a week. I have 3 backups (in 2 locations). Everytime a new one is created, the oldest is deleted. I figured if I need to roll back something, 3 weeks is more than enough to notice.
With borg or another deduplicating solution you could (probably) fit a year of daily in less space that the source takes. Of course depends how much the data changes over time. Highly recommend pika backup as borg desktop client. You can also easily do “smart” retention where only last week is daily, then weekly, monthly, yearly.
Back when I used OneDrive, it deleted an important but seldom used folder. It just wasn’t there anymore. No one noticed for 6 months, but luckily I had kept a backup each month so could restore it easily.
3 weeks is definitely not long enough for me to notice something missing, if it’s just a random chunk of my 700GB of important stuff. E.g. if a folder of my kids photos from 5 years ago suddenly disappeared, I probably wouldn’t notice it for months but would be devistated to find it missing when I eventually went looking for it.
I don’t host massive amounts of data. Just my contacts, calendars, grocery lists, rss feeds, that kind of stuff. All my pictures and movies are on my PC and backed up separately.