Disaster Recovery Planning
Disaster recovery (DR) planning prepares an organization to restore technology after a disruption that exceeds ordinary incident handling: a lost region or data center, destroyed or encrypted data, a compromised identity provider, or a critical vendor outage. It connects business priorities to the people, infrastructure, data, access, and decisions needed to bring back a usable service.
A DR plan isn't a document that proves compliance; it's a capability that has been demonstrated. The questions that matter are concrete: which services come back first, how much data can we afford to lose, who decides to fail over, and how do we know the recovered service actually works?
TL;DR
- Start with a business impact analysis and define the minimum acceptable service.
- Set RTO (how long you can be down) and RPO (how much data you can lose) per service, with named owners.
- Choose a recovery strategy per tier — backup and restore, pilot light, warm standby, or active-active — and fund it.
- Recovery is a dependency graph: identity, DNS, keys, and networking come before applications.
- Keep runbooks and emergency access independent of the systems being recovered.
- Exercise recovery regularly, including failback, and track gaps to closure.
Quick Example
A planning record for one scenario; tailor the values and acceptance criteria to the service.
Core Concepts
Business Impact Analysis
A business impact analysis (BIA) asks, for each business process: what happens as downtime grows — lost revenue, safety risk, regulatory breach, reputational harm — and what's the minimum level of service that keeps the organization viable? The output is a ranked list of services with tolerable downtime and data loss, which drives everything else.
RTO and RPO
- Recovery Time Objective (RTO) — the maximum acceptable time from disruption to restored service.
- Recovery Point Objective (RPO) — the maximum acceptable data loss, measured in time before the disruption.
An RPO of 24 hours can be met with nightly backups; an RPO of seconds needs continuous replication. Measure RTO to the moment an authorized user completes the critical transaction, not to "servers are up."
Service Tiers
Recovery Strategies
Infrastructure as code makes backup-and-restore and pilot-light strategies far faster, because environments can be recreated rather than rebuilt by hand.
Continuity Versus Recovery
Business continuity may use alternate staff, manual work, or a different supplier while technology is unavailable. Disaster recovery restores technology. A manual order log can keep work moving, but it creates records that must later be reconciled into the recovered system.
Recovery Is a Dependency Graph
Identity, name resolution, certificates, encryption keys, networking, storage, and vendor access are often prerequisites for applications. Map which services can start independently and which must wait. A frequent discovery during exercises: the recovery runbook lives in a wiki that requires single sign-on, which is down.
Ransomware and Compromise
After a suspected compromise, availability isn't the only goal. Coordinate with security response to identify a trusted recovery point from before the intrusion, rebuild on clean infrastructure, rotate credentials, and verify attackers no longer have access. Keep immutable or offline backups that the production admin credentials can't delete. See Backup Strategy.
Best Practices
Give Every Objective an Owner and a Budget
Business owners set tolerable disruption; technical teams demonstrate whether the design meets it. A gap between target and demonstrated capability is a risk that someone accountable must accept or fund — not something to quietly relabel.
Keep Emergency Access Independent
Maintain break-glass accounts, offline or separately hosted copies of runbooks and contact lists, and alternate communication channels. Test that they work when the primary identity provider and chat tools are unavailable.
Automate Recovery Steps
Scripted database promotion, DNS failover, and environment provisioning are faster and less error-prone under stress than manual console work.
Exercise in Increasing Realism
Start with tabletops to expose decision gaps, then isolated restores, then controlled failovers of real services. Time each step and compare against RTO.
Plan and Test Failback
A successful failover doesn't prove failback. Writes created at the recovery site need reconciliation and replication back before returning to the primary.
Fund the Findings
Assign every exercise gap an owner, due date, and next verification. An unstaffed corrective-action list leaves the recovery design unchanged.
Common Mistakes
Treating Backups as a DR Plan
Backups are necessary but not sufficient. Recovery also needs infrastructure, credentials, people, configuration, validation, and communication.
Hidden Shared Dependencies
A second region doesn't help if both depend on the same DNS provider account, deployment pipeline, key management service, or third-party API. Check administration, DNS, keys, deployments, vendors, and data replication for common failure.
Runbooks Behind the Failed System
Storing the only recovery runbook behind the identity provider being recovered makes it unreadable when you need it.
Untested RTOs
Recovery objectives that have never been demonstrated are hopes. Many organizations discover in their first real test that a "4-hour" restore takes two days.
Forgetting People
Plans that assume one expert is always available fail when that person is on vacation. Cross-train and document.
Comparison
FAQ
What is the difference between RTO and RPO?
RTO is how long a service can be unavailable before impact is unacceptable. RPO is how much recent data you can afford to lose. RTO drives how fast you must recover; RPO drives how often data must be copied.
Does every service need immediate recovery?
No. Prioritize by business impact and dependencies. Deferring reporting may be acceptable while order intake must return within an hour.
Is a backup enough for disaster recovery?
No. Recovery also needs infrastructure to restore into, credentials and keys, people who know the procedure, validation, and communication with users and stakeholders.
How often should we test disaster recovery?
Test critical services at least annually with a technical exercise, run tabletops more often, and retest after significant architecture changes.
Can a tabletop prove the RTO?
No. It tests decisions and assumptions. Proving recovery time requires an appropriately scoped technical exercise.
Related Topics
- Backup Strategy — Protecting and restoring data
- Incident Management — Coordinating the response while recovery happens
- High Availability — Designing systems that avoid needing DR
- Data Center Operations — Physical site resilience
- Runbooks — Writing procedures people can follow under stress