more updates

Author: AbhishekMallick-MS

articles/backup/backup-azure-vms-agentless-multi-disk-crash-consistent.md

@@ -1,41 +1,104 @@
 ---
-title: About agentless multi-disk crash consistent backup for Azure Virtual Machines by using Azure Backup
-description: Learn about agentless multi-disk crash consistent backup for Azure VMs by using Azure Backup via Azure portal.
-ms.topic: conceptual
+title: Back up Azure VM with agentless multi-disk crash consistent backup by using Azure Backup
+description: Learn how to configure backup for Azure VMs with agentless multi-disk crash consistent backup via Azure portal.
+ms.topic: how-to
 ms.date: 03/15/2024
 author: AbhishekMallick-MS
 ms.author: v-abhmallick
 ---
 
-# About agentless multi-disk crash consistent backup for Azure VMs (preview)
+# Back up Azure VM with agentless multi-disk crash consistent backup (preview)
+
+This article describes how to configure backup for Azure VMs with agentless multi-disk crash consistent backup (preview) and back up VM by using the Azure portal.
 
 Azure Backup supports agentless VM backups by using multi-disk crash-consistent restore points (preview). 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 preview) 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. 
 
-## When do I choose crash-consistent backup over application-consistent backup?
+## Configure backup for a new Azure VM with agentless multi-disk crash consistent backup
+
+The agentless crash consistent backup is available the *Enhanced VM backup policy* only. You need to set *crash-consistent backup* explicitly in this policy because *application/file-system consistent backup* is the default setting.
+
+To configure backup for a new Azure VM with agentless multi-disk crash consistent backup enabled, [create a Recovery Services vault](backup-create-recovery-services-vault.md#create-a-recovery-services-vault) and follow these steps:
+
+1. On the **Configure backup** blade, under **Policy sub type**, select **Enhanced** > **Create a new policy**. 
+
+2. On the **Create policy** blade, set the **Consistency type** to **Only crash consistent snapshot (Preview)** to enable *agentless crash consistent backup*.
+
+3. Select **OK**.
+
+## Move a VM from application/file-system consistent to crash consistent backup.
+
+If you have VMs backed up with Enhanced Policy, you can move them from agent based application/file-system consistent backups to agentless crash consistent backups by:
+
+- Changing their associated backup policy (recommended)
+- Editing the policy setting directly
+
+### Option 1: Change the VM backup policy to switch from application/file-system consistent backup to crash-consistent backup (recommended)
+
+Follow these steps:
+
+1. Go to a **Recovery Services vault**, and then select **Manage** > **Backup policies** to check the policy for the VMs you want to move to *crash-consistent backup*.
+
+
+2. Select the *backup policy*, and then on the **Modify policy** blade, select **Associated Items** to identify the VMs that you want to move to crash consistent backup.
+ 
+   >[!Note]
+   >Ensure that the VMs are supported for crash-consistent backups. Learn about the [supported scenarios](backup-azure-vms-agentless-multi-disk-crash-consistent.md#supported-scenarios-for-agentless-multi-disk-crash-consistent-vm-backup-preview).
+
+3. Go to the **Modify policy** blade, and then make a note of the settings in the policy to use the same in the new backup policy.
+
+4. Go to the **Backup policies** blade, and select **Add** to create a new policy.
+
+5. On the **Select policy type** blade, select **Azure Virtual Machine**.
+
 
-- If your workload is performance sensitive and can tolerate recovery from crash-consistent backups, crash-consistent backups help quiesce VM I/O for shorter period during backup. Crash-consistent backup doesn't use Volume Shadow Copy Service, VSS (for Windows) or fsfreeze (for Linux) to avoid the associated quiescing delays. 
+6. On the **Create policy** blade, select **Enhanced** as the **Policy sub type**, and then configure the new policy with the same backup frequency and retention as the existing policy. 
 
-- If you don't want to install the VM Agent or snapshot extension required for application consistent or file-system consistent snapshots in your Azure VM, use crash-consistent backups for an agentless backup solution.
+7. Set the **Consistency type** to **Only crash consistent snapshot (Preview)**, and then select **Create**.
+SetCrashConsistent.png <highlight setting crash consistent option>
 
-- If your operating system is not supported for application or file-system consistent backup, use crash consistent backups. Crash-consistent backup is operating system agnostic as it doesn't rely on the VM agent or snapshot extension.
+8. Go to the *existing policy*, select **Associated Items**, and then select **View details** corresponding to the VM you want to move to crash consistent backup.
 
-## When do I not use crash-consistent backups?
+9. Select **Backup policy** to go to the **Change Backup Policy** blade.
 
-- If your application can't tolerate recovery from crash consistent backups.
-- If you use pre/post scripts for Linux VM backups.
-- If you use read/write host caching and your workload is sensitive to cached data not being flushed before backup.
+10. On the **Change Backup Policy**     blade, change the backup policy to the new one you created, verify that it has the Consistency type set to Crash consistent, and then  select **Change**.
 
-## Pricing for agentless multi-disk crash-consistent backup
+   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.
 
-During preview, Azure VMs backed up with multi-disk crash consistent type is charged for 0.5 protected instance (PI) and the backup storage consumed.
+### Option 2: Modify the backup policy to change from application/file-system consistent backup to crash consistent backup
 
-## Supported scenarios for agentless multi-disk crash consistent VM backup (preview)
+If you don't want to create a new policy and move specific VMs, edit the **Consistency type** option in the existing policy.
 
-[!INCLUDE [backup-azure-agentless-multi-disk-crash-consistent-vm-backup-support-scenarios.md](../../includes/backup-azure-agentless-multi-disk-crash-consistent-vm-backup-support-scenarios.md)]
+Follow these steps:
 
+1.	Go to the *Recovery Services vault*, select **Backup policies**, and then choose an existing policy.
 
+2. On the **Modify policy** blade, select **Associated Items**. 
+
+   >[!Note]
+   >Ensure that all the VMs in the policy are supported for crash-consistent backups. Learn about the [supported scenarios](backup-azure-vms-agentless-multi-disk-crash-consistent.md#supported-scenarios-for-agentless-multi-disk-crash-consistent-vm-backup-preview).
+
+3. Go to the **Modify policy** blade, and set the **Consistency type** to **Only crash consistent snapshot (Preview)**, and then select **Update**.
+
+
+   You can monitor the *Modify backup policy* job on the **Backup jobs** blade. The *Configure backup jobs* triggered for each VM in the policy appear. 
 >[!Note]
->Multi-disk crash consistency might not succeed for disks configured with read or write host caching because writes that occur while the snapshot is taken might not be acknowledged by Azure Storage. If you need to maintain consistency, we recommend that you use the application-consistent backups.
+>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.
+
+ 
+
+
+
+
+
+
+
+
+
+
+
+
+
+.
 
 ## Next steps