Azure Backup is the Azure-based service you can use to back up (or protect) and restore your data in the Microsoft cloud. Azure Backup replaces your existing on-premises or off-site backup solution with a cloud-based solution that is reliable, secure, and cost-competitive.
With Azure Backup you can also back up your Windows Server (or Windows client) files and folders to Azure. For more information on how to back up Windows Server to Azure Recovery Services Vault, please check the following step by step guide from Microsoft.
The main component for backing up Windows Server to Azure is through the Microsoft Azure Recovery Services, known as MARS Agent. This, very clearly, is the Agent where all the data funnel through. With the Microsoft Azure Recovery Services (MARS) Agent installed on Windows, you can start backing up Files and Folders or System State only. This is a great solution for standalone servers and branch offices scenarios.
In this blog post, I will show you how to extend the mount time of instant restore files to Windows using Azure Backup, but before I get started, let’s have a quick overview on how Microsoft Azure Backup actually works.
How Microsoft Azure Backup Works
After you install and register the MARS agent to Azure, you can start creating backup policies. The backup policy is the schedule when recovery points are taken, and the length of time the recovery points are retained.
To set the backup schedule on the machine you want to back up, you need to use the Microsoft Azure Backup agent to create the backup policy for files and folders. If you are familiar with the traditional Windows Server backup feature, the Microsoft Azure Backup app looks the same. You can find it by searching for Microsoft Azure Backup on your machine.
How Instant Restore Files Works
Once your backup job is completed to Azure, you can use the Recover Data wizard in the Microsoft Azure Recovery Services (MARS) Agent to:
- Restore data to the same machine from which the backups were taken.
- Restore data to an alternate machine.
In the Recover Data wizard, you can recover:
- Individual files and folders, known as Instant Restore or Item-Level Recovery (ILR).
- System State.
When you restore a single item, behind the scene, the Instant Restore feature mount a Read Only recovery point snapshot as a recovery volume on your machine, and then you can browse the recovery volume and copy files to a local computer, thereby selectively restoring files.
You can see the mount volume in Disk Management.
Extend The Mount Time Of Instant Restore Files
When you mount the selected recovery point, the recovery volume (mount time) is extended to a maximum of 24 hours in case of an ongoing file-copy. And any backups scheduled during this time will run after the volume is unmounted.
Now the question is, what happened if you are restoring a large file (i.e. 500GB or 1TB), and the estimated restore time (file-copy) is greater than 24 hours?
Unfortunately, the restore will be interrupted as the volume will be automatically dismounted after 24 hours from the time it was mounted.
The good news is, you can extend the mount time beyond 24 hours so you can complete the recovery of the large file.
To do so, open registry editor on the machine where you have the MARS agent installed and create the following DWORD registry key. The value is the number of hours. In this example, I am setting the RecoveryJobTimeOut to 48 hours (2 days).
$RegistryPath = "HKLM:\SOFTWARE\Microsoft\Windows Azure Backup\Config\CloudBackupProvider" New-ItemProperty -Path $RegistryPath -Name "RecoveryJobTimeOut" -Value "48" -PropertyType DWORD -Force | Out-Null
Please note that the number of hours for the RecoveryJobTimeOut depend on two factors, the first one is, how large is the file size, and the second one is, how good your network bandwidth is to restore from Azure? Based on this information, you can set the right value here.
Thanks to Bhasker from the Azure Backup team for his help in getting to the bottom of this.
Hope this helps someone out there!
Do you want to explore the Azure Backup service in a deeper way, diving into the finer details of how things work, and to help people understand where it differs from what we traditionally used to do in the backup world. I highly recommend checking Azure Backup Deep Dive – Free Whitepaper.
Thank you for reading my blog.
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