Bootstrap an Azure VM in paired region from historical data

On this World Backup Day (celebrated on 31st March every year), let’s put our backups to good use. What if we can use backups for copy data management scenarios where you use backup data to create copies of your historical production data other than for restore purposes? You can do so by restoring from backups. But how do you bootstrap a VM in a different region from historical data? Until recently, this was not possible as Azure Backup only allowed restoring to the same region. With recently announced feature, Cross Region Restore, now you can restore a VM to a paired region using the backup copies.

How is it different than Azure Site Recovery?

On a fundamental level, Azure Site Recovery provides business continuity at the application level and is purposed for production data. Cross Region Restore (CRR) feature of Azure Backup is to provide resiliency for backup data. Site Recovery provides better RPO (up to 15 minutes) and only keeps data for maximum of 3 days. It is meant for business continuity. Cross Region Restore of Azure Backup is meant to provide resiliency for your backups. Until recently, you need to wait for Azure to declare that a region is down for your backup data to be useful and for you to trigger restore even though your backup data is replicated to a paired region. With CRR, you get the control on when to restore the VM to a paired region. We use this control to create a historical copy of the data.

How to enable Cross Region Restore?

Currently this feature is in preview and not available in all regions. You need Recovery Services vault of Azure Backup before you can begin. This blog assumes that you already have a vault and configured backup for the VM for which you want to create a copy in paired region. If not, you can follow this quick start tutorial on how to setup backup for an Azure VM in 5 minutes. Please refer to Setup cross region restore for instructions on how to enable this at recovery services vault.

Create a copy of VM in paired region with historical data

Once you have configured Cross Region Restore, Azure Backup will make your backup data available in the paired region. You can create a copy of VM from historical backup data by triggering cross region restore on the VM and selecting recovery points from paired region. Please refer to the Cross Region Restore on detailed steps on how to perform restore. After the restore is successful, you have bootstrapped a VM which is running based on historical data but in the paired region.

Can I only get disk data?

Above process will create a VM. However, there will be scenarios where you want to just get disk data but not the VM. Currently, managed disks only support LRS, which means that you can’t replicate VM data natively to paired region and have to use Azure Site Recovery for the complete VM to be available. No native solution for disk replication. With Cross Region Restore, you can trigger restore disks functionality of Azure Backup to get data in the paired region without creating a VM. This however has limitations that it can only support scenarios where you are fine with tolerating an RPO of maximum of 24 hours. There is a catch though! You can only restore all disks but not a selected disk. Hopefully, it will change in the future where you will be able to restore an individual disk and be able to get that in paired region.