| title | Back Up Azure VM with Agentless Multidisk Crash-Consistent Backup by using Azure Backup |
|---|---|
| description | Learn how to configure backup for Azure VMs with agentless multidisk crash-consistent backup via Azure portal. |
| ms.topic | how-to |
| ms.date | 07/25/2025 |
| author | AbhishekMallick-MS |
| ms.author | v-mallicka |
This article describes how to configure backup for Azure virtual machines (VMs) with agentless multidisk crash-consistent backup and back up VMs by using the Azure portal.
Azure Backup supports agentless VM backups by using multidisk crash-consistent restore points. The Enhanced VM backup policy now enables you to configure the consistency type of the backups (application-consistent restore points or crash-consistent restore points) for Azure VMs. This feature also enables Azure VM backup to retry the backup operation with crash-consistent snapshots (for supported VMs) if the application-consistent snapshot fails.
Note
The agentless multidisk crash-consistent VM backup feature is generally available. This release includes changes to billing. For more information, see the pricing details.
Review the supported scenarios and limitations of agentless multidisk crash-consistent backup. Learn more about supported scenarios.
You need to set crash-consistent backup explicitly in this policy because application/file system-consistent backup is the default setting.
The agentless crash-consistent backup is available with the Enhanced VM backup policy only.
To configure backup for a new Azure VM with agentless multidisk crash-consistent backup enabled, create a Recovery Services vault and follow these steps:
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On the Configure backup pane, under Policy sub type, select Enhanced > Create a new policy.
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On the Create policy pane, set Consistency type to Only crash consistent snapshot to enable agentless crash-consistent backup.
:::image type="content" source="./media/backup-azure-vms-agentless-multi-disk-crash-consistent/configure-agentless-vm-backup-for-new-vm-with-new-policy.png" alt-text="Screenshot that shows how to configure agentless crash-consistent backup for a new VM with a new backup policy." lightbox="./media/backup-azure-vms-agentless-multi-disk-crash-consistent/configure-agentless-vm-backup-for-new-vm-with-new-policy.png":::
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Select OK.
If you have VMs that are backed up with the Enhanced policy, you can move them from agent-based application/file system-consistent backups to agentless crash-consistent backups:
- Change their associated backup policy (recommended).
- Edit the policy setting directly.
Option 1: Change the VM backup policy to switch from application/file system-consistent backup to crash-consistent backup (recommended)
To change the VM backup policy, follow these steps:
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Go to a Recovery Services vault, and then select Manage > Backup policies to check the policy for the VMs that you want to move to crash-consistent backup.
:::image type="content" source="./media/backup-azure-vms-agentless-multi-disk-crash-consistent/vault-locate-policy.png" alt-text="Screenshot that shows how to locate all backup policies present in a vault." lightbox="./media/backup-azure-vms-agentless-multi-disk-crash-consistent/vault-locate-policy.png":::
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Select the backup policy, and then on the Modify policy pane, select Associated Items to identify the VMs that you want to move to crash-consistent backup.
:::image type="content" source="./media/backup-azure-vms-agentless-multi-disk-crash-consistent/policy-settings.png" alt-text="Screenshot that shows how to check associated items in a backup policy." lightbox="./media/backup-azure-vms-agentless-multi-disk-crash-consistent/policy-settings.png":::
Ensure that the VMs are supported for crash-consistent backups. Learn about the supported scenarios.
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Go to Modify policy, and then make a note of the settings in the policy to use the same in the new backup policy.
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Go to the Backup policies pane, and select Add to create a new policy.
:::image type="content" source="./media/backup-azure-vms-agentless-multi-disk-crash-consistent/add-backup-policy.png" alt-text="Screenshot that shows how to add a new backup policy." lightbox="./media/backup-azure-vms-agentless-multi-disk-crash-consistent/add-backup-policy.png":::
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On the Select policy type pane, select Azure Virtual Machine.
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On the Create policy pane, under Policy sub type, select Enhanced. Then configure the new policy with the same backup frequency and retention as the existing policy.
:::image type="content" source="./media/backup-azure-vms-agentless-multi-disk-crash-consistent/create-new-enhanced-backup-policy.png" alt-text="Screenshot that shows how to create a new backup policy with the same backup frequency and retention rules." lightbox="./media/backup-azure-vms-agentless-multi-disk-crash-consistent/create-new-enhanced-backup-policy.png":::
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Set Consistency type to Only crash consistent snapshot, and then select Create.
:::image type="content" source="./media/backup-azure-vms-agentless-multi-disk-crash-consistent/set-crash-consistent-policy.png" alt-text="Screenshot that shows how to set the crash-consistent policy." lightbox="./media/backup-azure-vms-agentless-multi-disk-crash-consistent/set-crash-consistent-policy.png":::
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Go to the existing policy, select Associated Items, and then select View details to see more information about the VM that you want to move to crash-consistent backup.
:::image type="content" source="./media/backup-azure-vms-agentless-multi-disk-crash-consistent/view-details-to-move-vm-crash-consistent.png" alt-text="Screenshot that shows how to view details of a VM." lightbox="./media/backup-azure-vms-agentless-multi-disk-crash-consistent/view-details-to-move-vm-crash-consistent.png":::
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Select Backup policy to go to the Change Backup Policy pane.
:::image type="content" source="./media/backup-azure-vms-agentless-multi-disk-crash-consistent/backup-policy-change.png" alt-text="Screenshot that shows how to initiate changing policy." lightbox="./media/backup-azure-vms-agentless-multi-disk-crash-consistent/backup-policy-change.png":::
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On the Change Backup Policy pane, change the backup policy to the new one that you created. Verify that it has Consistency type set to Crash consistent, and then select Change.
A Modifying protection notification and a Configure backup job in your vault for the VM is triggered. Monitor the notification or job to check if the crash-consistent backup policy is added successfully.
:::image type="content" source="./media/backup-azure-vms-agentless-multi-disk-crash-consistent/modify-vm-protection-policy-success-notification.png" alt-text="Screenshot that shows the success status for change in VM backup policy." lightbox="./media/backup-azure-vms-agentless-multi-disk-crash-consistent/modify-vm-protection-policy-success-notification.png":::
Option 2: Modify the backup policy to change from application/file system-consistent backup to crash-consistent backup
If you don't want to create a new policy and move only specific VMs, edit the Consistency type option in the existing policy.
To change from application/file system-consistent backup to crash-consistent backup, follow these steps:
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Go to the Recovery Services vault, select Backup policies, and then choose an existing policy.
:::image type="content" source="./media/backup-azure-vms-agentless-multi-disk-crash-consistent/vault-locate-policy.png" alt-text="Screenshot that shows how to check for all backup policies present in a vault." lightbox="./media/backup-azure-vms-agentless-multi-disk-crash-consistent/vault-locate-policy.png":::
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On the Modify policy pane, select Associated items.
:::image type="content" source="./media/backup-azure-vms-agentless-multi-disk-crash-consistent/policy-settings.png" alt-text="Screenshot that shows how to check the associated items in a backup policy." lightbox="./media/backup-azure-vms-agentless-multi-disk-crash-consistent/policy-settings.png":::
Ensure that all the VMs in the policy are supported for crash-consistent backups. Learn about the supported scenarios.
:::image type="content" source="./media/backup-azure-vms-agentless-multi-disk-crash-consistent/backup-policy-associated-items-edit.png" alt-text="Screenshot that shows the list of VMs associated with a backup policy." lightbox="./media/backup-azure-vms-agentless-multi-disk-crash-consistent/backup-policy-associated-items-edit.png":::
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Go to the Modify policy pane, set Consistency type to Only crash consistent snapshot, and then select Update.
:::image type="content" source="./media/backup-azure-vms-agentless-multi-disk-crash-consistent/modify-policy-crash-consistent.png" alt-text="Screenshot that shows how to check for the change in policy settings." lightbox="./media/backup-azure-vms-agentless-multi-disk-crash-consistent/modify-policy-crash-consistent.png":::
You can monitor the Modify backup policy job on the Backup Jobs pane. The Configure backup jobs triggered for each VM in the policy appear.
:::image type="content" source="./media/backup-azure-vms-agentless-multi-disk-crash-consistent/modify-policy-jobs.png" alt-text="Screenshot that shows how to monitor the policy change operation." lightbox="./media/backup-azure-vms-agentless-multi-disk-crash-consistent/modify-policy-jobs.png":::
If the job fails for an unsupported VM, revert the policy to opt out of crash-consistent backup and retry the update after you remove all unsupported VMs from the policy.