What is Azure Site Recovery (ASR)?
Answer
Azure Site Recovery (ASR) is a Disaster Recovery as a Service (DRaaS) solution that orchestrates replication, failover, and failback of Azure VMs, on-premises VMs, and physical servers. In a disaster, you fail over to Azure (or a secondary Azure region) to keep applications running. Key concepts: Recovery Time Objective (RTO): the maximum acceptable time to restore service — ASR typically achieves sub-hour RTO. Recovery Point Objective (RPO): maximum acceptable data loss — ASR typically achieves 30-second RPO for VMware VMs. Replication: continuous replication to the target region using crash-consistent and application-consistent recovery points. Test failover: validate your DR plan without impacting production by failing over to an isolated network.