Tutorial: Create and manage a Virtual Machine Scale Set with Azure PowerShell

A Virtual Machine Scale Set allows you to deploy and manage a set of virtual machines. Throughout the lifecycle of a Virtual Machine Scale Set, you may need to run one or more management tasks. In this tutorial you learn how to:

If you don't have an Azure subscription, create a free account before you begin.

Azure Cloud Shell

Azure hosts Azure Cloud Shell, an interactive shell environment that you can use through your browser. You can use either Bash or PowerShell with Cloud Shell to work with Azure services. You can use the Cloud Shell preinstalled commands to run the code in this article, without having to install anything on your local environment.

To start Azure Cloud Shell:

Option	Example/Link
Select Try It in the upper-right corner of a code or command block. Selecting Try It doesn't automatically copy the code or command to Cloud Shell.
Go to https://shell.azure.com, or select the Launch Cloud Shell button to open Cloud Shell in your browser.
Select the Cloud Shell button on the menu bar at the upper right in the Azure portal.

To use Azure Cloud Shell:

1. Start Cloud Shell.

2. Select the Copy button on a code block (or command block) to copy the code or command.

3. Paste the code or command into the Cloud Shell session by selecting Ctrl+Shift+V on Windows and Linux, or by selecting Cmd+Shift+V on macOS.

4. Select Enter to run the code or command.

Create a resource group

An Azure resource group is a logical container into which Azure resources are deployed and managed. A resource group must be created before a Virtual Machine Scale Set. Create a resource group with the New-AzResourceGroup command. In this example, a resource group named myResourceGroup is created in the EastUS region.

New-AzResourceGroup -ResourceGroupName "myResourceGroup" -Location "EastUS"

The resource group name is specified when you create or modify a scale set throughout this tutorial.

Create a Virtual Machine Scale Set

First, set an administrator username and password for the VM instances with Get-Credential:

$cred = Get-Credential

Now create a Virtual Machine Scale Set with New-AzVmss. To distribute traffic to the individual VM instances, a load balancer is also created. The load balancer includes rules to distribute traffic on TCP port 80, and allow remote desktop traffic on TCP port 3389 and PowerShell remoting on TCP port 5985:

New-AzVmss `
  -ResourceGroupName "myResourceGroup" `
  -VMScaleSetName "myScaleSet" `
  -OrchestrationMode "Flexible" `
  -Location "EastUS" `
  -Credential $cred

It takes a few minutes to create and configure all the scale set resources and VM instances. To distribute traffic to the individual VM instances, a load balancer is also created.

View the VM instances in a scale set

To view a list of VM instances in a scale set, use Get-AzVM as follows:

Get-AzVM -ResourceGroupName "myResourceGroup"

The following example output shows two VM instances in the scale set:

ResourceGroupName                Name Location          VmSize  OsType      ProvisioningState 
-----------------                ---- --------          ------  ------       ----------------- 
myResourceGroup   myScaleSet_instance1   eastus Standard_DS1_v2 Windows         Succeeded     
myResourceGroup   myScaleSet_instance2   eastus Standard_DS1_v2 Windows         Succeeded     

To view additional information about a specific VM instance, use Get-AzVM and specify the VM name.

Get-AzVM -ResourceGroupName "myResourceGroup" -name "myScaleSet_instance1" 

ResourceGroupName      : myresourcegroup
Id                     : /subscriptions/resourceGroups/myresourcegroup/providers/Microsoft.Compute/virtualMachines/myScaleSet_instance1
VmId                   : d27b5fde-d469-4087-b08f-87d0bd8df786
Name                   : myScaleSet_instance1
Type                   : Microsoft.Compute/virtualMachines
Location               : eastus
Tags                   : {}
HardwareProfile        : {VmSize}
NetworkProfile         : {NetworkInterfaces}
OSProfile              : {ComputerName, AdminUsername, WindowsConfiguration, Secrets, AllowExtensionOperations, RequireGuestProvisionSignal}
ProvisioningState      : Succeeded
StorageProfile         : {ImageReference, OsDisk, DataDisks}
VirtualMachineScaleSet : {Id}
TimeCreated            : 11/16/2022 11:02:02 PM

Create a scale set with a specific VM instance size

When you created a scale set at the start of the tutorial, a default VM SKU of Standard_D1_v2 was provided for the VM instances. You can specify a different VM instance size with the -VMSize parameter to specify a VM instance size of Standard_F1.

New-AzVmss `
  -ResourceGroupName "myResourceGroup" `
  -VMScaleSetName "myScaleSet" `
  -OrchestrationMode "Flexible" `
  -VMSize "Standard_F1" `
  -Location "EastUS" `
  -Credential $cred

Change the capacity of a scale set

When you created a scale set, two VM instances were deployed by default. To increase or decrease the number of VM instances in the scale set, you can manually change the capacity. The scale set creates or removes the required number of VM instances, then configures the load balancer to distribute traffic.

First, create a scale set object with Get-AzVmss, then specify a new value for sku.capacity. To apply the capacity change, use Update-AzVmss. The following example sets the number of VM instances in your scale set to 3:

# Get current scale set
$vmss = Get-AzVmss -ResourceGroupName "myResourceGroup" -VMScaleSetName "myScaleSet"

# Set and update the capacity of your scale set
$vmss.sku.capacity = 3
Update-AzVmss -ResourceGroupName "myResourceGroup" -Name "myScaleSet" -VirtualMachineScaleSet $vmss 

It takes a few minutes to update the capacity of your scale set. To see the number of instances you now have in the scale set, use Get-Az:

Get-AzVm -ResourceGroupName "myResourceGroup" 

The following example output shows that the capacity of the scale set is now 3:

ResourceGroupName                Name Location          VmSize  OsType    ProvisioningState 
-----------------                ---- --------          ------  ------    ----------------- 
myResourceGroup   myScaleSet_instance1   eastus Standard_DS1_v2 Windows       Succeeded     
myResourceGroup   myScaleSet_instance2   eastus Standard_DS1_v2 Windows       Succeeded     
myResourceGroup   myScaleSet_instance3   eastus Standard_DS1_v2 Windows       Succeeded   

Stop and deallocate VM instances in a scale set

To stop individual VM instances, use Stop-AzVm and specify the instance names.

Stop-AzVM -ResourceGroupName "myResourceGroup" -name "myScaleSet_instance1"

By default, stopped VMs are deallocated and don't incur compute charges. If you wish the VM to remain in a provisioned state when stopped, add the -StayProvisioned parameter to the preceding command. Stopped VMs that remain provisioned incur regular compute charges.

Start VM instances in a scale set

To start all the VM instances in a scale set, use Start-AzVmss.

Start-AzVmss -ResourceGroupName "myResourceGroup" -VMScaleSetName "myScaleSet" 

To start an individual VM instance in a scale set, use Start-AzVM and specify the instance name.

Start-AzVM -ResourceGroupName "myResourceGroup" -name "myScaleSet_instance1"

Restart VM instances in a scale set

To restart all the VMs in a scale set, use Restart-AzVmss.

Restart-AzVmss -ResourceGroupName "myResourceGroup" -VMScaleSetName "myScaleSet"

To restart an individual instance, use [Restart-AzVM] and specify the instance name.

Restart-AzVM -ResourceGroupName "myResourceGroup" -name "myScaleSet_instance1"

Clean up resources

When you delete a resource group, all resources contained within, such as the VM instances, virtual network, and disks, are also deleted. The -Force parameter confirms that you wish to delete the resources without an extra prompt to do so. The -AsJob parameter returns control to the prompt without waiting for the operation to complete.

Remove-AzResourceGroup -Name "myResourceGroup" -Force -AsJob

Next steps

In this tutorial, you learned how to perform some basic scale set creation and management tasks with Azure PowerShell:

Advance to the next tutorial to learn how to connect to your scale set instances.