How to Configure Azure Site Recovery for Disaster Recovery

Disasters—whether natural, technical, or human-made—can strike at any time. For businesses, downtime means lost productivity, revenue, and customer trust. That’s why having a disaster recovery (DR) strategy is critical.

Azure Site Recovery (ASR) is Microsoft’s disaster recovery as a service (DRaaS) offering. It helps businesses replicate workloads from on-premises or Azure regions to a secondary site, ensuring business continuity with minimal disruption.

In this article, we’ll explore:

• What Azure Site Recovery is
• Core components of ASR
• Step-by-step configuration
• Testing failover scenarios
• Best practices for disaster recovery planning

What Is Azure Site Recovery?

Azure Site Recovery enables organizations to:

• Replicate virtual machines (VMs) from on-premises or Azure to a secondary location.
• Orchestrate failover and failback during outages.
• Ensure minimal downtime and data loss with Recovery Point Objectives (RPOs).
• Simplify compliance by having a documented recovery process.

It works with:

• On-premises Hyper-V or VMware VMs
• Physical servers
• Azure VMs across regions

Core Components of ASR

1. Source Environment – The primary site where workloads currently run.
2. Recovery Services Vault – Central management hub in Azure for replication policies.
3. Replication Policies – Define RPO, retention, and sync frequency.
4. Failover Process – Automated orchestration for moving workloads to the recovery site.
5. Failback – Returning workloads to the primary environment after recovery.

Step 1: Prepare Your Environment

Before configuring ASR:

• Ensure Azure subscription with appropriate permissions.
• Set up networking between source and target (VPN or ExpressRoute if needed).
• Verify VM compatibility with ASR.
• Create or identify an Azure Storage Account for replication data.

Step 2: Create a Recovery Services Vault

1. In the Azure Portal, navigate to:
   Create a resource → Management & Governance → Recovery Services vault
2. Enter a name, subscription, resource group, and region.
3. Click Review + Create.

This vault acts as the central control point for your disaster recovery setup.

Step 3: Configure Site Recovery

1. Open your Recovery Services Vault.
2. Select Site Recovery → Replicate.
3. Choose your source environment:
   • On-premises → Azure
   • Azure → Azure (cross-region)
4. Select the target region and resource group.
5. Assign replication storage for VM data.

Step 4: Define Replication Policy

1. Under Site Recovery Infrastructure, create a replication policy.
2. Set:
   • Recovery Point Retention (e.g., 24 hours)
   • App-consistent snapshots (for critical workloads like databases)
3. Associate the policy with your VMs.

Step 5: Enable Replication

• Select the VMs to be protected.
• Enable replication to the recovery site.
• Monitor initial replication progress in the Jobs section.

Step 6: Test Failover

Testing ensures your disaster recovery plan works when needed.

1. In the Recovery Vault, go to Replicated Items.
2. Select a VM → Test Failover.
3. Choose a recovery point (latest or app-consistent).
4. Validate application functionality on the test VM.

⚡ Tip: Test failover doesn’t disrupt production workloads.

Step 7: Perform Planned and Unplanned Failover

• Planned Failover – Initiated during maintenance or migrations; ensures no data loss.
• Unplanned Failover – Used during outages; may result in minimal data loss depending on last sync.

Failover is orchestrated directly from the vault and can include automation runbooks for advanced recovery workflows.

Step 8: Failback to Primary Site

Once the primary site is restored:

1. Reverse replication back to the source.
2. Initiate failback to return workloads.
3. Validate systems before resuming production operations.

Best Practices for Azure Site Recovery

• Define RPO & RTO requirements per workload.
• Test failover regularly (quarterly or semi-annually).
• Use tags to organize protected workloads.
• Monitor ASR health with Azure Monitor and alerts.
• Combine ASR with Azure Backup for a full business continuity solution.
• Document and train staff on the disaster recovery runbook.

Conclusion

Disaster recovery is no longer optional—it’s essential. Azure Site Recovery provides a cost-effective, reliable way to protect workloads against outages and disasters.

By following the steps above—creating a recovery vault, configuring replication, testing failovers, and applying best practices—you can build a resilient, future-ready disaster recovery plan for your organization.