How to Set Up a Multi-Region Disaster Recovery Architecture on Azure for Virtual Machines with Azure Site Recovery (ASR)

Steps

Step 1: Configuring the Recovery Services Vault

• In the Azure portal, create a Recovery Services vault in the primary region.
• Define the vault’s settings, including replication policy for the desired RPO and RTO.
• Enable replication for the IaaS VMs by associating them with the Recovery Services vault.

Step 2: Setting Up Azure Site Recovery (ASR) Replication

• Configure the ASR replication policy:
  • Set the target region (secondary region) for replication.
  • Define the replication frequency based on RPO requirements.
  • Configure the retention settings for recovery points.
• Enable multi-VM consistency if you have VMs that must be recovered together (e.g., applications with multiple dependencies).
• Set up initial replication, ensuring all necessary VMs and disks are included in the replication scope.

Step 3: Configuring Networking in the Secondary Region

• Set up a Virtual Network (VNet) in the secondary region to host failed-over resources.
• If needed, configure IP address ranges and subnet structures to match those in the primary region.
• Enable network peering or connectivity between regions if inter-VM or cross-region communication is required during a failover.
• Optionally, configure a load balancer and/or VPN Gateway to handle network traffic after failover.

Step 4: Testing the Disaster Recovery Setup

• Conduct a test failover to validate the DR setup without affecting production resources:
  • Use the Azure Site Recovery failover option and select Test Failover.
  • Verify that replicated VMs start in the secondary region as expected.
  • Test application connectivity and network configuration to ensure smooth functionality.
• Monitor the test results and identify any issues that need addressing.

Step 5: Configuring Failover and Failback Policies

• Define failover priorities and configure dependencies to ensure an orderly recovery of resources.
• Set up automatic failover or manual failover options based on organizational needs.
• Configure the failback process to restore VMs and data from the secondary region to the primary region after the primary site is operational.
• Regularly review and update failover/failback policies as business requirements evolve.

5. Additional Information

• Azure Automation: Consider automating failover processes using Azure Runbooks for large-scale environments or complex configurations.
• Cost Optimization: Plan resource configurations in the secondary region to minimize costs during non-disaster scenarios (e.g., use lower-performance VMs).
• Compliance and Monitoring: Regularly monitor the replication health and test the failover periodically to ensure compliance with DR standards.
• Additional Resources: Link to official Microsoft documentation for ASR and best practices for configuring networking and security in multi-region setups.