Connect SQL Server instances to Azure at scale

This article describes how to connect multiple instances of SQL Server to Azure Arc as a single task. The easiest way to do that is by using Azure policy. Alternatively, you can connect multiple SQL Server instances installed on multiple Windows or Linux machines to Azure Arc using a script.


  • Each server has at least one instance of SQL Server installed


    SQL Server on Azure Arc-enabled servers does not support SQL Server Failover Cluster Instances.

  • The user onboarding Arc-enabled SQL Server resources has the following permissions:

    • Microsoft.AzureArcData/sqlServerInstances/read
    • Microsoft.AzureArcData/sqlServerInstances/write
  • The subscription has registered the following resource providers

    • Microsoft.AzureArcData
    • Microsoft.HybridCompute

Register resource providers

To register the resource providers, use one of the methods below:

  1. Select Subscriptions
  2. Choose your subscription
  3. Under Settings, select Resource providers
  4. Search for Microsoft.AzureArcData and Microsoft.HybridCompute and select Register

Connect at-scale using Azure Policy

You can automatically connect SQL Server instances on multiple Arc-enabled machines using an Azure policy definition called Configure Arc-enabled machines running SQL Server to have SQL Server extension installed. This policy definition is not assigned to a scope by default. If you assign this policy definition to a scope of your choice, it installs the Azure extension for SQL Server on all Azure Arc-enabled servers where SQL Server is installed. Once installed, the extension connects the SQL Server instances on the machine with Azure. After that, the extension runs continuously to detect changes of the SQL Server configuration and synchronize them with Azure. For example, if a new SQL Server instance is installed on the machine, the extension automatically registers it with Azure.

To create an Azure Policy assignment, you need the Resource Policy Contributor role assignment on the scope - subscription or resource group - that you are targeting the assignment to. Further, if you are going to create a new system assigned managed identity, you need the User Access Administrator role assignment in the subscription.


The Arc-enabled SQL Server resources for the SQL Server - Azure Arc resources are created in the same region and the resource group as the Server - Azure Arc resources on which they are hosted.


Because Azure extension for SQL Server synchronizes with Azure once an hour, it may take up to one hour before these resources are created after you create the policy assignment.

If you have the User Access Administrator and Resource Policy Contributor role assignments or have the subscription Owner role assignment, you can quickly enable at-scale registration using Azure Policy and a system assigned managed identity at the scope of an entire subscription or a specific resource group.

To do this,

  1. Navigate to the SQL Server - Azure Arc view in the Azure portal
  2. Select on the Automatic Arc-enabled SQL Server registration button at the top of the list.
  3. Select a subscription and optionally a resource group.
  4. Check the I accept the terms in the agreement checkbox.
  5. Select 'Enable'.

These steps create a new Azure Policy assignment of the Configure Arc-enabled machines running SQL Server to have SQL Server extension installed policy definition to the selected subscription and, optionally, a specific resource group scope. A new system assigned managed identity is created and granted the required permissions to onboard Arc-enabled SQL Servers. This new managed identity is used by the policy remediation to install the Azure extension for SQL Server.

Connect at-scale using Azure Policy assignment

If you want to select an existing user assigned managed identity or have more granular control over the configuration of the at-scale onboarding policy, you can create the Azure Policy assignment.

  1. Navigate to Azure Policy in the Azure portal and choose Definitions.
  2. Search for Configure Arc-enabled machines running SQL Server to have SQL Server extension installed. and click on the policy.
  3. Select Assign.
  4. Choose a Scope.
  5. Select Next, and Next.
  6. On the Remediation tab, click Create a remediation task.
  7. Choose System assigned managed identity (recommended) or User assigned managed identity and choose a managed identity which has User Access Administration and Log Analytics Contributor role assignments.
  8. Click Review + Create.
  9. Click Create.

See Azure Policy documentation for general instructions about how to assign an Azure policy using Azure portal or an API of your choice.

Connect multiple SQL Server instances using script

You can connect multiple SQL Server instances installed on multiple Windows or Linux machines to Azure Arc using the same script your generated for a single machine. The script will connect each machine and all installed SQL Server instances on it to Azure Arc.

Use Azure Active Directory service principal

For the best experience, use an Azure Active Directory service principal. A service principal is a special limited management identity that is granted only the minimum permission necessary to connect machines to Azure and to create the Azure resources for Azure Arc-enabled server and Azure Arc-enabled SQL Server. The service principal is safer than using a higher privileged account like a Tenant Administrator, and follows access control security best practices.

The installation methods to install and configure the Connected Machine agent requires that the automated method you use has administrator permissions on the machines. On Linux, use the root account. Windows, use a member of the Local Administrators group.

Before you get started, be sure to review the prerequisites and make sure that you've created a custom role that meets the required permissions.

Connect multiple instances

Each machine must have Azure PowerShell installed.

  1. Create the service principal. Use the New-AzADServicePrincipal cmdlet. Make sure to store the output in a variable. Otherwise, you won't be able to retrieve the password needed later.

    $sp = New-AzADServicePrincipal -DisplayName "Arc-for-servers" -Role <your custom role>
  2. Give the service principal permissions to access Microsoft Graph.


    • When you create a service principal, your account must be an Owner or User Access Administrator in the subscription that you want to use for onboarding. If you don't have sufficient permissions to create role assignments, the service principal might be created, but it won't be able to onboard machines. The instructions on how to create a custom role are provided in Required permissions.

    • The service principal must have Directory.ReadAll permissions in Microsoft graph. For instructions how to assign Directory permissions to a service principal, see Manage API permissions.

  3. Retrieve the password stored in the $sp variable:

    $credential = New-Object pscredential -ArgumentList "temp", $sp.PasswordCredentials.SecretText 
  4. Retrieve the value of the service principal's tenant ID:

    $tenantId= (Get-AzContext).Tenant.Id
  5. Copy and save the password, application ID, and tenant ID values using the appropriate security practices. If you forget or lose your service principal password, you can reset it using the New-AzADSpCredential cmdlet.


    Note that Azure Arc for servers doesn't currently support signing in with a certificate, so the service principal must have a secret to authenticate with.

  6. Download the PowerShell script from the Portal following the instructions in Connect your SQL Server to Azure Arc.

  7. Open the script in an administrator instance of PowerShell ISE and replace the following environment variables using the values generated during the service principal provisioning described earlier. These variables are initially empty.

  8. Execute the script on each target machine

Validate successful onboarding

After you connected the SQL Server instances to Azure, go to the Azure portal and view the newly created Azure Arc resources. You'll see a new Server - Azure Arc resource for each connected machine and a new SQL Server - Azure Arc resource for each connected SQL Server instance within approximately 1 minute. If these resources aren't created, it means something went wrong during the extension installation and activation process. See Troubleshoot Azure extension for SQL Server for the troubleshooting options.

Screenshot showing a successful onboard.

Troubleshoot Azure extension for SQL Server

Before you start, note the logs location. The extension log is created in this folder: C:\ProgramData\GuestConfig\extension_logs\Microsoft.AzureData.WindowsAgent.SqlServer\ExtensionLog_0.log

The deployer logs are created in this folder: C:\ProgramData\GuestConfig\extension_logs\Microsoft.AzureData.WindowsAgent.SqlServer\\deployer.log

The failure to create the Arc-enabled SQL Server resource could be caused by several issues.

Extension installation failed

Go to the connected server and check the deployer log. You should see the below messages.

[07/14/2021 18:56:45 UTC] [INFO] Status of service 'SqlServerExtension' before attempting start: Stopped [07/14/2021 18:56:45 UTC] [INFO] Status of service 'SqlServerExtension' after attempting start: Stopped

If you can't see it means the extension didn't install properly. Try the following steps.

  1. Check event logs to see if anything preventing installation. Try installing SqlServerExtension.msi from the following folder C:\Packages\Plugins\Microsoft.AzureData.WindowsAgent.SqlServer{version}. The installation UI may provide the error details.

  2. Close services app, server manager and retry one of the connection methods to install the extension, and see if that helps.

Extension installed but didn't start

Check the log files for any application errors.

The extension SQL Server isn't present on the machine

Check if SQL server installed.

Server - Azure Arc ARM resource was manually deleted

Check the extension log for the following record:

[7/14/2021 9:36:18 PM UTC] [ERROR]   [UploadServiceProvider]      [ExtensionHandlerStatusQueryError] ArcSqlInstancesRequest request is null, not sending data to RP.

This means the machine is no longer recognized as a connected server. Onboard the server to Azure Arc and retry one of the connection methods to install the extension.

Server managed identity has insufficient permissions

Check the extension log for the following record: [INFO] [UploadServiceProvider] [ExtensionHandlerArcUploadServicesNotifications] [AzureUpload] Arc post request failed with error: Forbidden message: {"ErrorDescription":{"ErrorCode":6,"Message":"The user has no access to the provided Azure resource."},"ResponseUrl":null}

Make sure the machine's managed identity has been assigned the Azure Connected SQL Server Onboarding role. See When machine already connected to Arc-enabled Server role assignment instructions.

The user didn't migrate the Arc-enabled SQL Server resource to the new resource provider

Check the extension log for the following record: [7/14/2021 5:35:04 PM UTC] [INFO] [UploadServiceProvider] [ExtensionHandlerArcUploadServicesNotifications] [AzureUpload] Arc for Sql Server upload response status: InternalServerError.

Make sure to migrate the Arc-enabled SQL Server resource to Microsoft.AzureArcData following these steps.

Next steps