In short
Disaster recovery planning means identifying your critical systems, setting recovery targets (how fast you must recover, RTO; how much data you can afford to lose, RPO), implementing off-site and immutable backups to meet those targets, documenting recovery procedures, and — crucially — testing the plan regularly so it works when a real disaster strikes.
What disaster recovery is (and isn't)
Disaster recovery (DR) is the set of backups, procedures and infrastructure that let you restore IT systems and data quickly after a disruption — hardware failure, fire, flood, ransomware or human error. It is not the same as simply 'having backups': a backup is only useful if it is recent, protected, off-site and proven to restore.
Understand RTO and RPO
Two targets drive every DR plan. RTO (Recovery Time Objective) is the maximum acceptable time to get a system back after an outage. RPO (Recovery Point Objective) is the maximum acceptable data loss, measured in time — an RPO of one hour means you back up at least hourly. Setting these for each critical system tells you what kind of backup and recovery solution you actually need.
Step by step: How to create a disaster recovery plan
Identify critical systems
List the systems and data your organisation cannot operate without, and rank them by importance. Recovery effort and cost should focus here first.
Set RTO and RPO targets
For each critical system, agree how quickly it must recover (RTO) and how much data loss is tolerable (RPO). These targets drive the whole design.
Implement off-site, immutable backups
Back up critical systems and data automatically to a separate, off-site location, using immutable backups that ransomware cannot alter or delete.
Document recovery procedures
Write clear, step-by-step recovery procedures and assign roles, so anyone can follow them under pressure — not just one person who might be unavailable.
Test the plan regularly
Run recovery tests to prove your backups and procedures actually work, and measure them against your RTO/RPO. Untested plans routinely fail when needed.
Review and update
Keep the plan current as systems, people and priorities change. A DR plan is a living document, not a one-off exercise.
Key takeaways
- DR = backups + procedures + infrastructure to recover quickly, not just 'having backups'.
- RTO (recovery time) and RPO (data loss) targets drive the whole design.
- Use off-site, immutable, tested backups.
- Untested plans fail — test and review regularly.
Frequently asked questions
How does disaster recovery work?
Disaster recovery keeps current backups or replicas of your systems in a safe, separate location, together with a documented plan to restore them. When disaster strikes, engineers follow the plan to bring systems back within an agreed time (RTO), losing no more than an agreed amount of data (RPO). Regular testing ensures it works when needed.
What are RTO and RPO?
RTO (Recovery Time Objective) is the maximum acceptable time to restore a system after an outage. RPO (Recovery Point Objective) is the maximum acceptable data loss, measured in time. Together they define how fast you must recover and how recent your backups must be, which drives the design of your DR solution.
How often should we test our disaster recovery plan?
At least annually, and ideally more often for critical systems or after significant changes. Regular testing is what separates a plan that works from one that only looks good on paper — many organisations discover backup or procedure gaps only when they test.