What is the 3-2-1-1-0 Strategy?
You’ve probably heard of the classic 3-2-1 rule. The 3-2-1-1-0 strategy takes it further, adding layers to address modern risks like ransomware and backup corruption. Here’s what each number stands for:
3 – Three copies of your data
Keep at least three copies of your data:
- 1 production copy (your live data)
- 2 backup copies
The more copies you have, the more redundancy you build — which greatly reduces the risk of complete data loss.
2 – Stored on two different types of media
Avoid a single point of failure. Store your data on two different storage types, such as:
- Local disk + external drive
- On-prem server + cloud backup
- SSD + tape (LTO)
This minimizes the chance that a hardware-specific failure wipes out all your copies.
1 – One off-site copy
At least one backup should be stored off-site, away from your primary location.
Examples include:
- Cloud storage
- Remote data center
- Tape backup stored in a different building
This protects you from physical disasters like fires, floods, or theft.
1 – One copy offline or immutable
This is the game-changer: one backup must be offline or immutable.
Why? Because modern threats (especially ransomware) often target connected backups.
Possible solutions:
- Write Once, Read Many (WORM) storage
- Air-gapped (physically disconnected) backups
- Immutable snapshots or object storage with retention policies
This is your insurance against malware or rogue actors trying to tamper with your backups.
0 – Zero errors after backup verification
Lastly, you want zero errors in your backup validation.
A backup is worthless if it’s corrupt or unrecoverable.
That means:
- Regular backup testing
- Restore drills
- Automated verification with alerting
No surprises when disaster strikes — that’s the goal.
Why Use the 3-2-1-1-0 Strategy?
In today’s world, where data is your most critical asset, having a backup isn’t enough — you need a reliable, tested, multi-layered strategy.
3-2-1-1-0 helps you:
- Protect against ransomware and insider threats
- Improve disaster recovery readiness
- Stay compliant with standards like GDPR, ISO 27001, and NIS2
- Achieve real business continuity
Final Thoughts
Data loss is not a matter of “if” but “when” — and the 3-2-1-1-0 strategy is your blueprint for resilience. It’s practical, scalable, and applicable whether you’re a solo developer, a startup, or a large enterprise.
Start implementing it today. Automate what you can. Test often. And make sure your backups are ready before you need them.
