Perform failover to a secondary region by using Azure Site Recovery

Azure Site Recovery (ASR) is a robust disaster recovery service that enables businesses to ensure continuity by replicating workloads from a primary site to a secondary location. When an outage or disruption occurs in the primary region, a failover can be initiated to the secondary region. The failover process ensures that applications and workloads continue to run with minimal downtime. For an Azure Administrator preparing for the AZ-104 Microsoft Azure Administrator exam, mastering ASR and its failover capabilities is essential.

Understanding Azure Site Recovery

Azure Site Recovery contributes to your business continuity and disaster recovery (BCDR) strategy by orchestrating replication, failover, and failback of virtual machines and physical servers. The service supports not only Azure VMs but also on-premises VMs and physical servers.

Setting Up Azure Site Recovery

1. Plan and Prepare for ASR

• Select the Replication Goal: Determine the source of your workloads and the target region where you want to replicate. Azure supports replicating between Azure regions (Azure-to-Azure), and from on-premises to Azure.
• Assess Your Environment: Use the Azure Site Recovery Deployment Planner to assess your environment’s readiness and estimate bandwidth requirements.
• Configure Azure Networks: Ensure that the virtual network in the secondary region is ready to host the VMs after failover.

2. Set Up the Recovery Services Vault

• Create a Recovery Services Vault: The vault is a storage entity in Azure that holds the replication data and maintains the failover configurations and settings.
• Set Up the Source Environment: For Azure-to-Azure, configure the source region by choosing the VMs you want to replicate.
• Set Up the Target Environment: Configure the target replication settings, including the resource group, storage account, and the virtual network in the secondary region.

3. Replicate Applications

• Enable Replication: Set up replication by specifying the VMs to include in the recovery plan and the target region settings.
• Initial Replication: An initial replication will occur, sending the data to the secondary region.
• Continuous Replication: ASR provides continuous replication with asynchronous replication for Azure VMs.

4. Implement a Recovery Plan

• Create a Recovery Plan: Organize your VMs into recovery plans, which define the sequence and method of failover for a group of VMs.
• Customize Recovery Plan: Include necessary manual actions, scripts, and Azure Automation runbooks within the recovery plan to ensure smooth operation during failover.

5. Test the Failover

• Conduct a Test Failover: Perform a test failover to validate whether the secondary region VMs will work as expected without impacting the primary region.
• Review the Test Failover Results: Validate application functionality and review Azure metrics for performance and availability.

6. Perform a Failover

• When a disruption is detected:
• Initiate the Failover: Carry out a failover by triggering your recovery plan. This action will orchestrate the failover according to the predefined steps.
• Resolve Issues: If any issues occur during failover, troubleshoot and resolve them based on the diagnosis information available.
• Complete Failover: After the failover has completed, you can commit the failover to indicate that the secondary region is now the active region.

7. Failback to the Primary Region

• Once the primary region is restored:
• Re-Protect the VMs: Enable replication back to the original location to reverse the replication direction.
• Perform a Failback: Initiate a failback to the primary region by again following a recovery plan designed for failback operations.

Monitoring and Management

Monitor your Site Recovery environment using Azure Monitor and Recovery Services Vault metrics and logs. Ensure that you regularly review replication health, test failover results, and audit operations using the Azure portal or Azure PowerShell.

Best Practices and Considerations

• RPO and RTO: Understand your Recovery Point Objective (RPO) and Recovery Time Objective (RTO) requirements and ensure ASR meets them.
• Automation and Scripting: Implement Azure Automation and scripts for complex recovery scenarios.
• Cost Management: Estimate and optimize the costs associated with replication, storage, and compute resources in the secondary region.

In conclusion, performing a failover to a secondary region using Azure Site Recovery is a critical operation that requires careful planning, setup, and management. An Azure Administrator should be thoroughly familiar with the steps and best practices to ensure an effective BCDR strategy. Through practical experience and the use of Azure’s detailed documentation, administrators can gain confidence in managing and executing failover operations.