How does Azure handle disaster recovery at a regional level?

Azure disaster recovery at the regional level uses region pairs — each Azure region is paired with another region in the same geography (e.g., East US ↔ West US, North Europe ↔ West Europe). Benefits: Sequential updates (Microsoft never updates paired regions simultaneously, reducing update-related outage risk). Data residency (replication within the same geography for compliance). Key services: Azure Site Recovery: VM replication and failover orchestration across regions. Geo-redundant storage (GRS): Blob Storage replicates asynchronously to paired region. Active Geo-Replication (Azure SQL): readable secondary databases in other regions. Cosmos DB multi-region writes. Failover groups for Azure SQL with automatic failover. Design for both RTO (recovery time) and RPO (data loss tolerance) — different services offer different guarantees.