What is a disaster recovery plan?
A disaster recovery plan defines how to restore a service after a major outage or data loss.
How it works and where it is used
Record critical services, dependencies, responsible people, alternate locations and communication paths. RTO is a target restoration time; RPO is tolerated data-loss window. Without testing, these are only aspirations. A database backup may not restore a site without secrets, DNS and provider access.
Limits, safety and selection criteria
Keep backups separate, protected from unauthorized changes and regularly restore-tested. Tabletop and real recovery exercises expose gaps. Update contacts and architecture as they change; a vague document first opened during disaster is not enough. A disaster recovery plan describes the order in which services return after an outage or data loss. Recovery point objective sets tolerable data loss; recovery time objective sets tolerable downtime. Both influence backup and infrastructure costs. Having a backup does not prove it can be restored. Rehearsals should test access, dependent services, DNS changes and data consistency. Name decision makers and a user communication channel in advance. Update the plan as the system changes and use exercise findings to improve it.