Disaster Recovery Basics
Disaster recovery (DR) is the plan for restoring systems and data after a major disruption — a breach, a failure, a flood. It is the technical arm of business continuity, and it turns a worst-case event from an existential threat into a bounded, recoverable one. Like an incident response plan, its value is proven only when tested.
RTO and RPO: the two metrics that drive everything#
DR planning starts with two questions, each with a number:
| Metric | Question | Drives |
|---|---|---|
| RTO (Recovery Time Objective) | How fast must it be back? | Recovery architecture |
| RPO (Recovery Point Objective) | How much data can we lose? | Backup frequency |
A system with a one-hour RTO and near-zero RPO needs very different (and costlier) infrastructure than one that can be down a day and lose an hour of data. Setting these per system, based on business impact, is what makes DR investment rational rather than one-size-fits-all.
Why testing is non-negotiable#
A DR plan that has never been executed is a set of assumptions. Real recoveries surface broken backups, missing dependencies, undocumented steps, and RTOs that were fantasy. Testing — restoring systems in a controlled way, timing it against the RTO — converts those assumptions into verified capability.
Disaster recovery builds on backups and readiness. More at the Defense & Hardening hub.
Frequently asked questions#
What is disaster recovery?
Disaster recovery (DR) is the set of plans and procedures for restoring IT systems and data after a major disruption — a cyberattack, hardware failure, or natural disaster. It is the technical side of business continuity, focused on getting critical systems back online within acceptable timeframes and with acceptable data loss.
What are RTO and RPO?
RTO (Recovery Time Objective) is how quickly a system must be restored after an outage — the maximum tolerable downtime. RPO (Recovery Point Objective) is how much data loss is acceptable, measured as the maximum age of data you can afford to lose. Together they drive backup frequency and recovery architecture.