3-2-1 backup strategy
Volume × criticality → scheme and cost
Input
Scheme
cloud: 400 ₴/mo
1. Primary copy
Working device
2. Local backup
1× 2TB HDD = 4 500 ₴ one-time
3. Off-site (cloud)
400 ₴/mo = 4 800 ₴/yr
3-2-1: 3 copies, 2 different media, 1 off-site (fire/theft/ransomware). Sync ≠ backup: deleted files sync too. Versioning (snapshots) is the only ransomware protection.