Disaster Recovery Plan with Azure Site Recovery

Overview

Enterprises and cloud solutions teams, for the most part, recognize the importance of a disaster recovery solution. To define and select a disaster recovery plan, one of the first steps is to conduct a business impact analysis. This process helps identify applications that support critical business processes, assesses the business impact of an outage, and guides the creation of the best possible disaster recovery plan. After you’ve completed the analysis and identified the critical applications, you’ll need to create a disaster recovery strategy. Typically, this means:

• Making continuous improvements in the failure points and identifying the talented workforce or administrators to manage the disaster recovery segment
• Setting targets for recovery time objectives (RTOs) and recovery purpose objectives (RPOs)
• Choosing the best product or service based on your requirements
• Identifying all the necessary software and hardware resources
• Testing the disaster recovery strategy regularly

Planning Your Site Recovery

• Establishing an ASR vault.
• Introducing the ASR extension to every VM for it to connect to your ASR vault.
• Replicating virtual machine discs to nearby temporary storage.
• Construct virtual machines from duplicate discs in the secondary area.
• Creating a replica of an original VM discs or storage account

Steps to Create a Vault for Recovery Services

You need to establish a vault for recovery services. So that the vault keeps the track of the replication in the process and shows how the process will take place. To prevent losing it with your other data if the azure region explodes, the vault is situated in the backup region.

To create the ASR vault:

Step 1: Type in Browser www.portal.azure.com and get logged into your Azure Portal.

Step 2: Type in the search box Recovery Service Vaults then the ASR Vault page will open.

Step 3: Click Create, provide details for creating recovery vaults and then click on Review + Create

Note: for the resource, the group creates a new resource group or provides an existing one.

After that provide a region where it will failover the site.

Steps to Enable Replication

After creating a vault, you should configure it by activating replication, or what Azure calls “Site Recovery.”

Step 1: Click Enable Site Recovery while still on your ASR vault page, as illustrated below

You will see the replication options when your Recovery Services Vault opens.

Step 2: As shown below, click on Enable replication.

Step 3: Now, make all the setup changes required to enable replication.

• Source Location
• Azure Virtual Machine Deployment Model
• Source Subscription
• Source Resource Group
• Disaster Recovery between availability zones

Step 4: Select the virtual machines you wish to replicate in the Source resource group provided above and click Next. After configuration of all inputs click next to enable replication.

Several events take place after ASR starts the replication process:

• ASR install the ASR extension on each VM to communicate with them.
• The ASR extension authenticates with the Site Recovery vault.
• A resource group with the suffix “- ASR” is created.
• ASR creates managed discs for each VM and vNet, with names beginning with”-ASR.”
• While the disc writes are being transferred to a local storage account, which serves as a dedicated cache in the source region, the vault starts duplicating the VMs. These writes are handled before being forwarded to the location you’ve chosen for failover.
• The vault processes local storage data and sends it to an ASR-created storage account or managed discs in the destination region.
• Every five minutes, ASR generates crash-consistent recovery points. Only the data present on the disc now of the snapshot is included in a crash-consistent snapshot. Contrary to an app-consistent snapshot, it excludes all data from memory.

Checking Replication Status:

In the dashboard navigate to the recovery services vault it may take some time to deploy after that you will see your resources marked as healthy and you can see the architecture.

Conclusion

As reported by Gartner, a strength of the Azure Site Recovery tool is that “Microsoft has high success rates and speed of failover, with over 90% of ASR failovers completed in 10 minutes and 99.9% completed within 30 minutes

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