What is the primary difference between high availability and disaster recovery in cloud architecture?
Show answer and explanation
Answer: B
High availability minimizes downtime from ordinary component failures by eliminating single points of failure — for example, spreading VMs across availability zones — within the primary deployment. Disaster recovery is the process and tooling for restoring the workload after a region-level catastrophe, typically from backups or a replica in another region, when local redundancy has been overwhelmed. HA prevents disruption from routine failures; DR recovers from disasters, and a mature architecture uses both.
Why the other options are wrong
- A. They are related but distinct: HA works continuously to keep service up, while DR exists for events severe enough to defeat HA-level redundancy.
- C. The distinction is not by resource type — both HA techniques and DR plans apply to databases, VMs, storage, and messaging alike.
- D. The split is not automatic-versus-manual: HA failover is usually automatic, but DR can also be automated, for example with Azure Site Recovery failover.