[nine_k]

The wisdom of 1990s was that if you have one copy of data on your disk, you may as well have zero copies.

It became more pronounced in late 1990s when disks became more ubiquitous and the race for the lower price likely made them less reliable.

After that the idea of backing things up, no matter where they are recorded initially, feels very natural.

[Tijdreiziger]

That's still the wisdom.

The 3-2-1 backup rule: keep at least 3 copies of your data on at least 2 storage media, and keep at least 1 copy offsite.

[vardump]

> The wisdom of 1990s was that if you have one copy of data on your disk, you may as well have zero copies.

Still true.

[daveslash]

Along similar lines: If you haven't tested or dry-run your restore procedures, you may as well not have backups either.

That applies more for things like SQL databases and the like, more than personal files on disk. But yeah.... if you haven't tried to restore your database or other data repository from a backup file that you've squirreled away, then you effectively don't have a backup either.

[noizejoy]

I’d slightly amend the analogy into “an untested backup is akin to having a lottery ticket for your backups”. Maybe you win or maybe you don’t.

Old floppies are also like lottery tickets in that sense.