I have daily backups, weekly, monthly and yearly. All but yearly is deleted after a certain time, but yearly I keep forever.

I was backing up multiple places on my LAN but than half of my place flooded, so lamenat and carpet was ripped up, one of my pi 5’s was misplaced with a NVMe drive and another was lost. Than just down the street 3 house went up in flames had the wind been blowing just a little south my condo complex would have been burnt to the ground. After the fire fighters were telling us to get back further and further I had my main pi 5 that had all the backups of everything important on another NVMe drive and a few other things ready to go if the firefighters started banging on my door telling me it was time to leave. I wish I could honestly say that was the day I decided to get a VPS and start my back up, but I was still hoping my father would let me set up a pi with a drive big enough to do back ups at his place. It sounds like he will but he is concerned about security risks about my VPN, funny thing is my back up pi would be the most secure thing hooked up to his modem/router and I wouldn’t want his stuff touching my stuff and with how my LAN and VPN are set up they would have a hard time doing it. Anywho I have a domain hosted by EasyDNS, and just went and looked at their VPS options and got some year long plan and set up cron jobs to take the stuff I want to backup and use age to encrypt it and than it is sent to my VPS each age container is than deleted after there is something of the same name but 3 days iterations older and deletes it.

How long do you keep your backups?

Yes, I have that exernal HDD lying around somewhere near the PC, and it was at least 4 or 5 times that I backed up a lot of files on it.

I think I keep it for more than 10 years now.

I learned I pretty much never need old data for my hobby selfhosting stuff. So I do 4 weeks. I'll notice if something breaks within 4 weeks and fix it. I occasionally do manual backups, for example when migrating stuff and keep them for longer. And I got some old stuff like in xkcd 1360.

I suppose I could do more, but I also want the privacy policy of my online services to say: x weeks and all the logs and unnecessary data is gone.

As long as I have space. My backups are on dedicated drives, and as they run out of space the old ones are deleted.

I just buy new HDDs.

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.

My VPS gets a weekly rsync to my home server. I keep ten deduplicated copies for weeks gone by. The current week also gets synced off-site with encryption.

[forget]
keep-daily = 10
keep-weekly = 4

Daily backups are cheap because of de-duplication. I keep a few weekly backups in case it takes me a bit to notice something went wrong. I don't usually back up logs.

I could probably drop the weekly backups without much risk, but I've got the space.

Let me put it this way: I have a removable harddisk with my files from the universities' VAX 11/780 in storage. Long enough?

Zero or one backups depending on the type of data generally.

For a system if it can't be redeployed from a list of requirements then I Foundationally ducked up. It means either I'm depending on something fragile, unknowable or over complicated.

Raw data on the other hand goes on a raid array. If I need more redundancy then that, then a single extra off site backup on a cd or something.

A back up on the same drive as the original isn't a backup. It's a waste of space, and a stupid idea.

A system that requires excessive nonsense is not reliable.

If I have a on and off site back up and both fail. Then either the world is literally fucking on fire and it doesn't matter. Or someone dropped a bomb on my storage.

Either way I have bigger problems at that point.