Cloud Storage for Backup: Why Sync Is Not Backup, and How to Set Up a Real 3-2-1 Strategy
Cloud sync (Dropbox, Sync.com, pCloud) and cloud backup (IDrive, Backblaze) are different products. A real backup strategy uses both. Here is the 3-2-1 rule applied to the audited / privacy-first cloud-storage providers.
Sync is not backup
Cloud sync mirrors a folder across devices: a change on one device propagates to all others. If you delete a file on one device, it deletes everywhere — usually with a 30-day trash retention as the only recovery window. Cloud backup takes scheduled snapshots: a deleted file remains recoverable for the configured retention period (often 30 days, sometimes years). IDrive markets itself as backup-first; Backblaze Computer Backup is a pure backup product. Proton Drive, Sync.com, pCloud, and MEGA market sync — their version-history features add limited backup-like properties but do not replace a real backup.
The 3-2-1 backup rule
The 3-2-1 rule, popularised by IT-industry guidance for decades, states: keep 3 copies of important data, on 2 different types of media, with 1 copy off-site. Applied to consumer cloud storage in 2026: copy 1 is the original on your device. Copy 2 is a local backup (external SSD, NAS, Time Machine). Copy 3 is the off-site cloud backup. The cloud copy is what survives a fire, theft, or ransomware attack on the local copies. Sync alone does not satisfy the rule because the synced cloud copy is not independent — a delete propagates.
Picking a backup provider
IDrive Personal 5 TB at $69.65 first-year is the cheapest published per-TB rate for backup-first use (per idrive.com/pricing). Backblaze offers two products: B2 Cloud Storage at $6/TB/mo (API-first, you bring your own backup tool like restic) and Backblaze Computer Backup at $9/mo or $99/yr per computer for unlimited storage. The Computer Backup product is the simplest consumer choice; B2 is for users who want to script with restic / borg / rclone+crypt. Both Backblaze products have published US-West, US-East, and EU-Central regions.
Adding E2E to a backup strategy
If the backup destination is server-side encrypted only (Backblaze Computer Backup, IDrive default mode), the 3-2-1 strategy still works against the most common threats (ransomware, hardware failure, theft). It does not protect against the cloud provider being compelled to disclose data. To add E2E, either enable the provider's optional zero-knowledge mode (IDrive private-key mode), or layer a tool: restic supports AES-256 client-side encryption against any S3 backend including B2; rclone+crypt provides similar transparent encryption against any rclone-supported backend.
Sources
IDrive pricing: idrive.com/pricing. Backblaze B2 pricing: backblaze.com/cloud-storage/pricing. Backblaze B2 security: backblaze.com/cloud-storage/security. Proton Drive: proton.me/drive/pricing. Sync.com: sync.com/pricing. restic: restic.net. rclone crypt: rclone.org/crypt. All URLs accessed 2026-04-30.