Azure Documentation

Backing Up Azure Managed Disks

This document provides comprehensive guidance on backing up your Azure Managed Disks, a critical aspect of data protection and disaster recovery strategies.

Why Backup Managed Disks?

Regular backups are essential for several reasons:

• Data Recovery: Recover from accidental data deletion, corruption, or application errors.
• Disaster Recovery: Ensure business continuity in the event of a regional outage or major disaster.
• Compliance: Meet regulatory requirements for data retention and availability.
• Point-in-Time Restore: Restore disks to a specific point in time, minimizing data loss.

Azure Backup for Managed Disks

Azure Backup provides a robust and integrated solution for backing up your Managed Disks. It offers the following key features:

• Application-consistent backups: For Windows and Linux VMs, ensuring data integrity by quiescing applications before the backup.
• Crash-consistent backups: For other scenarios, capturing the disk state as it is at the moment of the backup.
• Cross-region restore: Restore backups to a different Azure region for enhanced disaster recovery.
• Policy-based management: Define backup schedules, retention periods, and backup types (full, incremental).
• Automated backups: Schedule backups to run automatically at defined intervals.

How to Configure Disk Backups

You can configure backups for your Managed Disks using the Azure portal, Azure CLI, or Azure PowerShell.

Using the Azure Portal

1. Navigate to the Azure Backup service in the Azure portal.
2. If you don't have a Recovery Services vault, create one.
3. In the vault, select Backup.
4. Under "Where is your workload running?", select Azure.
5. Under "What do you want to backup?", select Virtual Machine.
6. Select the virtual machine that has the disks you want to back up.
7. Configure the backup policy, which includes:
   • Backup Schedule: Frequency and time of backups.
   • Retention Policy: How long backups are kept (e.g., daily, weekly, monthly, yearly).
   • Instant Restore: Enable faster restores by storing full backups for a configurable duration.
8. Click Enable backup.

Using Azure CLI

Here's an example of how to enable backup for a VM using Azure CLI:

az backup vault create --resource-group MyResourceGroup --name MyBackupVault
az backup protection enable-for-vm --resource-group MyResourceGroup --vault-name MyBackupVault --vm MyVMName --policy MyPolicyName
                

Using Azure PowerShell

Here's an example of how to enable backup for a VM using Azure PowerShell:

$vault = Get-AzRecoveryServicesVault -ResourceGroupName "MyResourceGroup" -Name "MyBackupVault"
Enable-AzRecoveryServicesBackupProtection -ResourceGroupName "MyResourceGroup" -Name "MyVMName" -Policy "MyPolicyName" -VaultId $vault.ID
                

Backup Policy Details

When creating or managing a backup policy, consider the following:

• Recovery Point Objective (RPO): The maximum acceptable amount of data loss measured in time. For instance, an RPO of 1 hour means that data loss should not exceed 1 hour.
• Recovery Point Retention: How long backup copies are retained. This can vary based on compliance needs and operational requirements.
• Backup Frequency: How often backups are taken (e.g., daily, hourly).
• Instant Restore: This feature retains full backup data in the vault for a specified number of days (default is 5 days), enabling faster restores.

Restoring Disks from Backups

Restoring disks is a straightforward process, typically initiated from the Recovery Services vault or directly from the VM's backup instance. Refer to the Disk Restore documentation for detailed steps.

Best Practices for Disk Backups

• Regularly test restores: Ensure your backup and restore process works as expected.
• Use appropriate retention policies: Balance compliance needs with storage costs.
• Monitor backup jobs: Keep track of backup job status to identify and resolve failures promptly.
• Consider cross-region backups: For critical workloads, implement backups in a secondary region for disaster recovery.
• Secure your backup data: Utilize Azure Backup's security features to protect your backup data from accidental deletion or malicious attacks.