Offsite backup
Also known as: offsite copy, remote backup, cloud copy, geo-redundant backup
An offsite backup is a copy of your data stored somewhere other than your primary location -- typically the cloud or a remote data center.
It's the '1' in the 3-2-1 rule and the key to surviving site-level disasters, because no local event can wipe out a copy that isn't there.
Offsite backup, explained at three levels
At home
An offsite backup is a copy of your files kept away from your office -- usually in the cloud. That way, if your building has a fire, flood, or break-in, your data survives somewhere else and you can get it back.
At work
Keeping all your backups in the office is risky: one disaster could destroy the originals and the backups together. An offsite copy -- typically cloud-based -- means a local catastrophe can't erase your only path to recovery.
At home
Offsite backups can be automated to the cloud so there's no manual handling to forget. Geographic separation matters -- an offsite copy across town survives a building fire, while a copy in another region survives a wider disaster. Encryption keeps the offsite data private in transit and at rest.
At work
The offsite copy is your last line of defense, so it should ideally be immutable (unchangeable) to resist ransomware that reaches your network. Recovery speed from offsite depends on data size and bandwidth, which is why many businesses pair a fast local backup with the offsite copy.
At home
Effective offsite strategy considers restore logistics: seeding large initial backups, bandwidth for recovery, and whether the provider offers physical media shipment for huge restores. Retention on the offsite copy should be long enough to recover from slow-burning corruption or infection discovered late.
At work
Design the offsite tier around RPO/RTO and threat model: immutable object storage with versioning defeats ransomware deletion, cross-region replication defends against regional events, and documented recovery procedures ensure the offsite copy is actually usable. Test restores from offsite specifically -- it's the copy you'll rely on when everything else is gone.
Real-world examples
At home
A break-in at Sophie's office took her laptop and the external backup drive sitting next to it. Everything would have been lost -- except her MSP also sent an automatic encrypted copy to the cloud each night. That offsite copy let her recover fully.
At work
Carlos kept diligent local backups, but a flood destroyed both the server and the backup NAS in the same room. Only the offsite cloud backup, in a distant data center, survived -- and it was the sole reason the business could restore and reopen.
Common confusions
- A backup drive kept in the same building is offsite enough — If it's in the same location, a single fire, flood, or theft can destroy it along with the originals. Offsite means genuinely separate -- ideally the cloud or a remote site.
- Offsite backup and cloud sync are the same — Sync mirrors current files, propagating deletions and ransomware. A proper offsite backup keeps separate, versioned, ideally immutable copies you can restore from a clean point.
- One offsite copy means I don't need local backups — Restoring large amounts of data from offsite can be slow. A local copy provides fast everyday restores, while offsite covers disasters -- the 3-2-1 rule wants both.
For analysts
Confirm your offsite backup is genuinely separate and, ideally, immutable. The test question: if your entire office were destroyed tonight, is there a copy of your data somewhere else that ransomware couldn't have touched? If not, that's your top priority.
History & origin
Before broadband, offsite backup meant physically rotating tapes or drives to a bank vault or an employee's home -- effective but slow and error-prone. Affordable cloud storage in the 2010s automated offsite copies over the internet, removing the human step that so often failed. Ransomware's habit of destroying local backups made a truly separate offsite copy indispensable rather than optional.