The 3-2-1 backup rule: how to never lose your data
Three copies, two different devices, one off-site. A simple rule that protects you from hardware failure and ransomware alike.
Over Mobilszerviz’s ten years and our team’s decades in system administration, one thing has never changed: data loss always comes unexpectedly. The good news is that a simple rule almost completely prevents it.
What does 3-2-1 mean?
- 3 copies of your data: the original plus two backups.
- On 2 different devices, for example your computer and an external drive or NAS.
- 1 copy elsewhere, for example in the cloud, so it survives fire, burglary or ransomware.
At home
In practice: automatic cloud backup (iCloud, OneDrive, Google Photos) plus an external drive with a full backup once a month. Don’t forget the photos on your phone.
In a small business
Here backups must be automatic, monitored and checked. The cloud copy should be immutable, so ransomware can’t encrypt the backup as well.
The most important step: test the restore
A backup is only worth something if you can restore from it. Try it regularly – or leave the checking to us.