Resize a Windows VM created in the classic deployment model

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Important

Classic VMs will be retired on March 1, 2023.

If you use IaaS resources from ASM, please complete your migration by March 1, 2023. We encourage you to make the switch sooner to take advantage of the many feature enhancements in Azure Resource Manager.

For more information, see Migrate your IaaS resources to Azure Resource Manager by March 1, 2023.

This article shows you how to resize a Windows VM, created in the classic deployment model using Azure Powershell.

When considering the ability to resize a VM, there are two concepts which control the range of sizes available to resize the virtual machine. The first concept is the region in which your VM is deployed. The list of VM sizes available in region is under the Services tab of the Azure Regions web page. The second concept is the physical hardware currently hosting your VM. The physical servers hosting VMs are grouped together in clusters of common physical hardware. The method of changing a VM size differs depending on if the desired new VM size is supported by the hardware cluster currently hosting the VM.

Important

Azure has two different deployment models for creating and working with resources: Resource Manager and Classic. This article covers using the Classic deployment model. Microsoft recommends that most new deployments use the Resource Manager model. You can also resize a VM created in the Resource Manager deployment model.

Add your account

You must configure Azure PowerShell to work with classic Azure resources. Follow the steps below to configure Azure PowerShell to manage classic resources.

  1. At the PowerShell prompt, type Add-AzureAccount and click Enter.
  2. Type in the email address associated with your Azure subscription and click Continue.
  3. Type in the password for your account.
  4. Click Sign in.

Resize in the same hardware cluster

To resize a VM to a size available in the hardware cluster hosting the VM, perform the following steps.

  1. Run the following PowerShell command to list the VM sizes available in the hardware cluster hosting the cloud service which contains the VM.

    Get-AzureService | where {$_.ServiceName -eq "<cloudServiceName>"}

  2. Run the following commands to resize the VM.

    Get-AzureVM -ServiceName <cloudServiceName> -Name <vmName> | Set-AzureVMSize -InstanceSize <newVMSize> | Update-AzureVM

Resize on a new hardware cluster

To resize a VM to a size not available in the hardware cluster hosting the VM, the cloud service and all VMs in the cloud service must be recreated. Each cloud service is hosted on a single hardware cluster so all VMs in the cloud service must be a size that is supported on a hardware cluster. The following steps will describe how to resize a VM by deleting and then recreating the cloud service.

  1. Run the following PowerShell command to list the VM sizes available in the region.

    Get-AzureLocation | where {$_.Name -eq "<locationName>"}

  2. Make note of all configuration settings for each VM in the cloud service which contains the VM to be resized.

  3. Delete all VMs in the cloud service selecting the option to retain the disks for each VM.

  4. Recreate the VM to be resized using the desired VM size.

  5. Recreate all other VMs which were in the cloud service using a VM size available in the hardware cluster now hosting the cloud service.

A sample script for deleting and recreating a cloud service using a new VM size can be found here.

Next steps