Cloud storage makes a file available on several devices. That convenience can look like a backup, but synchronization and backup solve different problems.
What synchronization does
A sync service keeps selected folders consistent. Edit a document on a laptop and the new version appears on a phone. Delete a file and that deletion may also spread everywhere. Version history or a recycle bin can save the day, but retention periods and limits vary.
A backup creates a recoverable copy designed for restoration. It should preserve data even when the working copy is deleted, corrupted, encrypted by ransomware or lost with a device.
Build protection around the failure
List what cannot be replaced: family photos, tax records, creative projects and account recovery information. Then consider several failures.
If a laptop dies, a cloud copy may be enough. If an account is locked or compromised, a local copy matters. If theft, fire or flooding affects the home, an off-site copy matters.
A common starting point is three copies on two kinds of storage, with one copy off-site. That might mean the working files, an external drive and an encrypted cloud backup. The exact arrangement matters less than avoiding one account, device or location as the only point of failure.
Details worth checking
- Does the service synchronize, back up or do both?
- How long are deleted files and older versions retained?
- Is data encrypted during transfer and storage?
- Who controls the encryption key?
- Can you export everything in ordinary file formats?
- Have you successfully restored a sample folder?
Keep backup drives disconnected when they are not running a backup if ransomware is a concern. Protect cloud accounts with strong authentication and save recovery codes offline.
Storage capacity is not the same as resilience. A terabyte in one place is still one place.
The best backup system is automatic enough to run regularly and simple enough to restore under stress. Test it before an emergency, while an unsuccessful restore is merely inconvenient rather than devastating.
Sources
- NIST SP 800-209, Security Guidelines for Storage Infrastructure: https://csrc.nist.gov/pubs/sp/800/209/final
- CISA, Back Up Business Data: https://www.cisa.gov/audiences/small-and-medium-businesses/secure-your-business/back-up-business-data