Glossary
Sauvegarde 3-2-1
The universally recommended backup rule: 3 copies of your data, on 2 different media, with 1 off-site.
"We have a backup" is the most dangerous sentence in cybersecurity. Most SMBs we audit have a single copy on the office NAS — which gets encrypted along with everything else when ransomware lands.
The 3-2-1 rule summarises good practice: 3 copies of the data (original + 2 backups), on 2 different media (e.g. local disk + cloud), with 1 off-site (at a provider or in a geographically separate data centre).
For a French SMB, the typical implementation is: original on Microsoft 365 or Google Workspace, dedicated third-party backup (Datto, Synology Active Backup, Acronis) on a local NAS, and a second automated backup to Backblaze or an EU data centre. Quarterly restore test mandatory — an untested backup is an imaginary backup.