How to migrate your classic storage accounts to Azure Resource Manager

Article
09/05/2024

Azure will retire classic storage accounts on August 31, 2024. To preserve the data in any classic storage accounts, you must migrate them to the Azure Resource Manager deployment model by that date. After you migrate your account, all of the benefits of the Azure Resource Manager deployment model will be available for that account. For more information about the deployment models, see Resource Manager and classic deployment.

This article describes how to migrate your classic storage accounts to the Azure Resource Manager deployment model. For more information, see Migrate your classic storage accounts to Azure Resource Manager by August 31, 2024.

Overview of the migration process

Before you get started with the migration, read Understand storage account migration from the classic deployment model to Azure Resource Manager for an overview of the process.

To migrate your classic storage accounts, you should:

Identify classic storage accounts in your subscription.
Locate and delete any disk artifacts in classic accounts.
Migrate your classic storage accounts.
Update your applications to use Azure Resource Manager APIs.

Identify classic storage accounts in your subscription

Portal
PowerShell

To list classic storage accounts in your subscription with the Azure portal:

Navigate to the list of your storage accounts in the Azure portal.
Select Add filter. In the Filter dialog, set the Filter field to Type and the Operator field to Equals. Then set the Value field to microsoft.classicstorage/storageaccounts.

To list classic storage accounts in your subscription with PowerShell, run the following command:

Get-AzResource -ResourceType Microsoft.ClassicStorage/storageAccounts

Locate and delete any disk artifacts in a classic account

Classic storage accounts may contain classic (unmanaged) disks, virtual machine images, and operating system (OS) images. To migrate the account, you will need to delete these artifacts first.

Important

If you do not delete classic disk artifacts first, the migration may fail.

To learn about migrating unmanaged disks to managed disks, see Migrating unmanaged disks to managed disks.

Portal
PowerShell

To delete disk artifacts from the Azure portal, follow these steps:

Navigate to the Azure portal.
In the Search bar at the top, search for Disks (classic), OS Images (classic), or VM Images (classic) to display classic disk artifacts.
Locate the classic disk artifact to delete, and select it to view its properties.
Select the Delete button to delete the disk artifact.

For more information about errors that may occur when deleting disk artifacts and how to address them, see Troubleshoot errors when you delete Azure classic storage accounts, containers, or VHDs.

Migrate a classic storage account

The process of migrating a classic storage account involves four steps:

Validate. During the Validation phase, Azure checks the storage account to ensure that it can be migrated.
Prepare. In the Prepare phase, Azure creates a new general-purpose v1 storage account and alerts you to any problems that may have occurred. The new account is created in a new resource group in the same region as your classic account.

At this point, your classic storage account still exists. If there are any problems reported, you can correct them or abort the process.
Check manually. It's a good idea to make a manual check of the new storage account to make sure that the output is as you expect.
Commit or abort. If you're satisfied that the migration has been successful, then you can commit the migration. Committing the migration permanently deletes the classic storage account.

If there are any problems with the migration, then you can abort the migration at this point. If you choose to abort, the new resource group and new storage account are deleted. Your classic account remains available. You can address any problems and attempt the migration again.

For more information about the migration process, see Understand storage account migration from the classic deployment model to Azure Resource Manager

Note

Accounts left in a Prepare migration state more 30 days may have their migrations committed on your behalf. If you need more than 30 days to validate your migration to Azure Resource Manager, you can abort the current migration and restart it when you are ready.

You can migrate a classic storage account to the Azure Resource Manager deployment model with the Azure portal or PowerShell.

Portal
PowerShell

To migrate a classic storage account to the Azure Resource Manager deployment model with the Azure portal:

Navigate to your classic storage account in the Azure portal.
In the Settings section, select Migrate to ARM.
Select Validate to determine migration feasibility.
After a successful validation, select Prepare button to simulate the migration.
If the Prepare step completes successfully, you'll see a link to the new resource group. Select that link to navigate to the new resource group. The migrated storage account appears under the Resources tab in the Overview page for the new resource group.

At this point, you can compare the configuration and data in the classic storage account to the newly migrated storage account. You'll see both in the list of storage accounts in the portal. Both the classic account and the migrated account have the same name.
If you're not satisfied with the results of the migration, select Abort to delete the new storage account and resource group. You can then address any problems and try again.
When you're ready to commit, type yes to confirm, then select Commit to complete the migration.

Important

There may be a delay of a few minutes after validation is complete before the Prepare button is enabled.

To migrate a classic storage account to the Azure Resource Manager deployment model with PowerShell, you must use the Azure PowerShell Service Management module. To learn how to install this module, see Install and configure the Azure PowerShell Service Management module. The key steps are included here for convenience.

Note

The cmdlets in the Azure Service Management module are for managing legacy Azure resources that use Service Management APIs, including classic storage accounts. This module includes the commands needed to migrate a classic storage account to Azure Resource Manager.

To manage Azure Resource Manager resources, we recommend that you use the Az PowerShell module. The Az module replaces the deprecated AzureRM module. For more information about moving from the AzureRM module to the Az module, see Migrate Azure PowerShell scripts from AzureRM to Az.

First, install PowerShellGet if you don't already have it installed. For more information on how to install PowerShellGet, see Installing PowerShellGet. After you install PowerShellGet, close and reopen the PowerShell console.

Next, install the Azure Service Management module. If you also have the AzureRM module installed, you'll need to include the -AllowClobber parameter, as described in Step 2: Install Azure PowerShell. After the installation is complete, import the Azure Service Management module.

Install-Module -Name Azure -AllowClobber
Import-Module -Name Azure

Log into your account by running Add-AzureAccount. Then call Select-AzureSubscription to set your current subscription. Remember to replace the placeholder values in brackets with your subscription name:

Add-AzureAccount -Environment AzureChinaCloud
Select-AzureSubscription -SubscriptionName <subscription-name>

To validate that the account is ready for migration, call the Move-AzureStorageAccount command. Remember to replace the placeholder values in brackets with the name of your classic storage account:

$accountName = "<storage-account>"
Move-AzureStorageAccount -Validate -StorageAccountName $accountName

Next, prepare the account for migration:

Move-AzureStorageAccount -Prepare -StorageAccountName $accountName

Check the configuration for the prepared storage account with either Azure PowerShell or the Azure portal. If you're not ready for migration, use the following command to revert your account to its previous state:

Move-AzureStorageAccount -Abort -StorageAccountName $accountName

Finally, when you're satisfied with the prepared configuration, move forward with the migration and commit the resources with the following command:

Move-AzureStorageAccount -Commit -StorageAccountName $accountName

Update your applications to use Azure Resource Manager APIs

After you migrate your classic storage account to Azure Resource Manager, you must update your applications and scripts to use Azure Resource Manager APIs. The Azure Storage resource provider is the implementation of Azure Resource Manager for Azure Storage.

Azure Storage provides SDKs for convenience in calling the Azure Storage resource provider APIs:

You can also use the latest versions of Azure PowerShell and Azure CLI to manage your migrated storage accounts:

To learn more about resource providers in Azure Resource Manager, see Resource providers and resource types.