What is ASR?
Azure Site Recovery (ASR) is a disaster recovery (DR) solution that replicates workloads to a secondary location.
If the primary site (datacenter or Azure region) goes down, workloads can fail over to the replica, ensuring business continuity.
Key Features
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Replication: Continuously replicates VMs, physical servers, or other workloads to another Azure region (or on-prem → Azure).
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Failover: Switch workloads to the replica site during outages.
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Failback: Return workloads to the primary site once it’s back online.
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Integration: Works with both Azure VMs and on-premises environments.
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Automation: Supports recovery plans to orchestrate failover in sequence.
Typical Use Cases
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Protect Azure VMs by replicating them to a secondary Azure region.
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Protect on-premises VMware/Hyper-V VMs by replicating to Azure.
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Meet compliance requirements for disaster recovery planning.
Confusion Buster 🚨
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Backup vs ASR
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Backup = Protects data with copies stored in Recovery Services Vault. Long-term, point-in-time recovery.
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ASR = Keeps workloads running by replicating them to another site. Real-time or near real-time recovery.
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Exam trap: If the question says “failover to another region”, answer is ASR, not Backup.
Simple Example
A bank runs critical applications in Azure.
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They configure ASR to replicate workloads from East US → West US region.
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During an outage in East US, ASR fails over the workloads to West US.
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Once East US is restored, workloads fail back seamlessly.
Exam Tip
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If scenario mentions data retention → Backup.
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If it mentions disaster recovery / failover → ASR.
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If it says compliance-driven long-term restore → Recovery Services Vault.
What to Expect in the Exam
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Direct Q: “Which Azure feature provides disaster recovery through replication and failover?” → Azure Site Recovery.
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Scenario: “Company must keep apps running during a regional outage.” → ASR.
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Trick Q: “ASR is used for long-term backup storage.” (False — that’s Azure Backup).