In today's digital landscape, businesses must prioritize data protection and disaster recovery to ensure continuity and resilience. Azure Site Recovery (ASR) is a powerful disaster recovery solution that enables organizations to replicate and recover their applications and data across different Azure regions or on-premises environments. This article will guide you through setting up Azure Site Recovery for various disaster recovery scenarios, including prerequisites, configuration steps, and best practices.

Understanding Azure Site Recovery

Azure Site Recovery is a cloud-based service that helps ensure business continuity by enabling the replication of virtual machines (VMs) and applications to a secondary location. In the event of an outage or disaster, ASR allows organizations to failover to the secondary site quickly, minimizing downtime and data loss. Key features of ASR include:

Automated Replication: Seamlessly replicate VMs to Azure or a secondary data center.
Failover and Failback: Easily switch operations to the secondary site and revert back when the primary site is restored.
Application Consistency: ASR ensures data integrity by coordinating the replication of all VMs involved in an application.
Testing Failover: Conduct non-disruptive testing of your disaster recovery plan to ensure readiness.

Prerequisites for Setting Up Azure Site Recovery

Before diving into the setup process, ensure you meet the following prerequisites:

Azure Subscription: You need an active Azure subscription to access Azure Site Recovery.
Supported Infrastructure: Verify that your infrastructure meets the ASR requirements, including supported operating systems, VM configurations, and network setups.
Azure Resource Group: Create or identify an existing resource group in your Azure subscription to hold your ASR resources.
Recovery Services Vault: A Recovery Services vault is required to manage the ASR configuration and store replicated data.
Network Configuration: Set up appropriate networking between your primary site and Azure, including VPN or ExpressRoute connections if replicating from on-premises environments.
Permissions: Ensure you have the necessary permissions to create resources in Azure and configure ASR.

Step-by-Step Setup of Azure Site Recovery

Create a Recovery Services Vault

Log in to the Azure Portal
Navigate to Create a resource and search for Recovery Services vault.
Click Create and fill in the following details:
Name: Enter a unique name for the vault.
Subscription: Choose your Azure subscription.
Resource Group: Select an existing resource group or create a new one.
Location: Choose the Azure region where the vault will be created.
Click Review + create and thenCreate.

Configure the Recovery Services Vault

After the vault is created, navigate to the Recovery Services vault in the Azure portal.
Click on Site Recovery in the vault settings.
Under Getting Started, select Prepare Infrastructure.
Choose the appropriate replication scenario based on your infrastructure (e.g., Azure to Azure, on-premises to Azure, etc.).

Enable Replication

Select the Source and Target environments:
For on-premises scenarios, choose the appropriate source infrastructure (VMware, Hyper-V, physical servers).
For Azure scenarios, select the Azure region to which you want to replicate.
Click Next to proceed to the Target configuration.
Select the target resource group and network where replicated VMs will reside.
Choose the replication policy. You can use the default policy or create a custom one based on your RPO (Recovery Point Objective) requirements.
Click Enable replication.

Configure Source Infrastructure

For On-Premises Environments

Install the ASR Configuration Server:
Download the ASR Configuration Server installer from the Azure portal.
Follow the installation instructions to set up the Configuration Server on a physical or virtual machine.
After installation, register the server with your Recovery Services vault.

Set Up the Process Server:
The Process Server is responsible for data transfer between the on-premises VMs and Azure. Configure the Process Server in the same way as the Configuration Server.

Install the ASR Mobility Service:
For each VM you want to replicate, install the ASR Mobility Service, which handles the replication of data to Azure.

For Azure Environments

Select Virtual Machines:
Navigate to Virtual Machines in the Azure portal.
Select the VM you want to replicate and click on Enable replication.

Assign to the Recovery Services Vault:
 Choose the Recovery Services vault created earlier and select the replication policy.
 Enable replication.

Monitor Replication Status

After enabling replication, monitor the status of the VMs in the Azure portal.
Navigate back to the Recovery Services vault and click on Site Recovery Replicated items.
Check the replication status of each VM to ensure successful synchronization with Azure.

Test Failover

In the Replicated items section, select the VM you want to test.
Click on Test failover.
Choose the failover location (Azure or on-premises) and select the desired network configuration for the test environment.
Click OK to initiate the test failover. Azure will create a separate instance of the VM for testing, ensuring no impact on the production environment.

Perform a Planned Failover (Optional)

If you need to perform a planned failover (for maintenance or other reasons), select the VM in the Replicated items section.
Click on Planned failover.
Select the desired network and confirm the failover. This process will synchronize any changes made after the last replication.

Execute a Failback (If Necessary)

After a failover, you may need to revert back to the original primary site. This process is known as failback.
Select the VM in the Replicated items section and click on Failback.
Follow the prompts to synchronize data from the secondary site back to the primary site.

Best Practices for Azure Site Recovery

Regular Testing: Regularly test your failover and failback procedures to ensure your disaster recovery plan is effective and up to date.
Monitor Replication Health: Use Azure Monitor and alerts to keep track of the health of your replicated VMs and the overall ASR setup.
Document Procedures: Maintain comprehensive documentation of your disaster recovery procedures, including step-by-step instructions for failover and failback.
Stay Updated: Keep your ASR configuration server and mobility services updated to ensure compatibility and security.
Leverage Automation: Consider using Azure Automation to streamline and automate failover and failback processes.

Setting up Azure Site Recovery is a crucial step in ensuring the resilience and continuity of your business operations. By following the steps outlined in this article, you can effectively configure ASR to protect your applications and data from various disaster scenarios. Remember to regularly test your disaster recovery plan, monitor your replication status, and stay informed about updates to maintain an effective recovery strategy. With Azure Site Recovery, you can rest assured that your business is prepared to handle disruptions and maintain operations with minimal downtime.