Data loss has many causes: faulty hardware, accidental deletion, theft, fire - and, increasingly, ransomware that deliberately targets backups too. The proven answer to this is the 3-2-1 rule.

What does 3-2-1 mean?

3 copies of your data: the original plus two backups.
2 different media: for example a NAS and cloud storage - a failure of one medium must not affect both backups.
1 copy off-site: geographically separate, for example in a data center. It protects against fire, break-ins, or encryption within the local network.

What else you should pay attention to

Immutable backups

Modern ransomware actively searches for reachable backups. At least one backup should be immutable or offline, so it can't be tampered with afterward.

Test your recovery

A backup only counts as a backup once recovery has been demonstrably proven to work. Schedule regular restore tests and document them.

Define your recovery time

How long can your business afford to be down at most? This question determines your backup intervals and choice of technology - from simple file backup to a virtualized disaster-recovery environment.

Conclusion

The 3-2-1 rule isn't rocket science, but it does require discipline in operations: monitoring, testing, and clear responsibilities. That's exactly what we take care of with our Online Backup service - automatic, encrypted, and monitored every day.