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--- title: Resize a virtual machine description: Change the VM size used for an Azure virtual machine. ms.service: azure-virtual-machines ms.subservice: sizes ms.topic: how-to ms.date: 11/10/2025 ms.custom: compute-cost-fy24, devx-track-azurecli, devx-track-azurepowershell, devx-track-terraform # Customer intent: "As a cloud administrator, I want to resize a virtual machine to a suitable SKU so that I can efficiently allocate resources based on workload demands while minimizing downtime." --- # Change the size of a virtual machine **Applies to:** :heavy_check_mark: Linux VMs :heavy_check_mark: Windows VMs :heavy_check_mark: Flexible scale sets This article shows you how to change an existing virtual machine's [VM size](../sizes.md). After you create a VM, you can scale it up or down by changing the VM size. This process works whether the VM is currently running or has already been deallocated. In some cases, you must deallocate the VM before resizing. Deallocation may be required if the new size isn’t available on the hardware cluster currently hosting the VM. Even when deallocation isn’t required, changing the size of a running VM will cause it to restart. For this reason, resizing a VM should be considered a disruptive operation, especially for stateful workloads. > [!WARNING] > If the virtual machine is currently running, changing its size will cause it to restart. > > Deallocating the VM also releases any dynamic IP addresses assigned to the VM. The OS and data disks are not affected. > > If a resize operation fails, the VM model will still display the requested size, but the VM will continue running on its previous size until the resize is successfully allocated. This behavior applies to both the Azure portal, and all GET operations, as the displayed size always reflects the latest applied configuration, not the actual running size. > ## Choose the right SKU When resizing a VM, it's important to choose the right SKU based on the signals from the VM to determine whether you need more CPU, memory, or storage capacity: - If the VM is running a CPU-intensive workload, such as a database server or a web server with high traffic, you may need to choose a SKU with more CPU cores. For more information, see [Compute optimized](/azure/virtual-machines/sizes/overview?#compute-optimized) sizes. - If the VM is running a memory-intensive workload, such as a machine learning model or a big data application, you may need to choose a SKU with more memory. For more information, see [Memory optimized](/azure/virtual-machines/sizes/overview#memory-optimized) sizes. - If the VM is running out of storage capacity, you may need to choose a SKU with more storage. For more information, see [Storage optimized](/azure/virtual-machines/sizes/overview#storage-optimized) sizes. - If your VM uses Premium Storage, make sure that you choose an **s** version of the size to get Premium Storage support. For example, choose Standard_E4**s**_v3 instead of Standard_E4_v3. For more information on choosing the right SKU, you can use the following resources: - [Sizes for VMs in Azure](../sizes.md): This article lists all the VM sizes available in Azure. - [Azure VM Selector](https://azure.microsoft.com/pricing/vm-selector/): This tool helps you find the right VM SKU based on your workload type, OS and software, and deployment region. ## Limitations 1. You can't resize a VM size that has a local temp disk to a VM size with no local temp disk and vice versa. The only combinations allowed for resizing are: - VM (with local temp disk) -> VM (with local temp disk); and - VM (with no local temp disk) -> VM (with no local temp disk). For a work-around, see [How do I migrate from a VM size with local temp disk to a VM size with no local temp disk? ](../azure-vms-no-temp-disk.yml#how-do-i-migrate-my-windows-vm-from-a-size-with-local-temp-disk-to-a-vm-size-with-no-local-temp-disk---). The work-around can be used to resize a VM with no local temp disk to VM with a local temp disk. You create a snapshot of the VM with no local temp disk > create a disk from the snapshot > create VM from the disk with appropriate [VM size](../sizes.md) that supports VMs with a local temp disk. 2. You can't resize a VM size that has a SCSI-based VM to a VM size that has a remote NVMe-enabled VM. For a workaround, see [How can I resize a SCSI-based VM to a remote NVMe-enabled VM of a different size?](../enable-nvme-remote-faqs.yml#how-can-i-resize-a-scsi-based-vm-to-a-remote-nvme-enabled-vm-of-a-different-size-) ## Change the VM size Select an option for changing the VM size: ### [Portal](#tab/portal) To change the VM size using the Azure portal: 1. Open the [Azure portal](https://portal.azure.com). <br/><br/> 1. Type *virtual machines* in the search. Under **Services**, select **Virtual machines**. 1. In the **Virtual machines** page, select the virtual machine you want to resize. 1. In the left menu, in the **Availability + scale** section, select **size**. 1. Pick a new compatible size from the list of available sizes and then select **Resize**. If your VM is still running and you don't see the size you want in the list, stopping the virtual machine may reveal more sizes. ### [PowerShell](#tab/powershell) To change the size of a VM using PowerShell: 1. Set the resource group and VM name variables. Replace the values with information of the VM you want to resize. ```powershell $resourceGroup = "myResourceGroup" $vmName = "myVM" ``` 1. List the VM sizes that are available on the hardware cluster where the VM is hosted. ```powershell Get-AzVMSize -ResourceGroupName $resourceGroup -VMName $vmName ``` 1. Resize the VM to the new size. ```powershell $vm = Get-AzVM -ResourceGroupName $resourceGroup -VMName $vmName $vm.HardwareProfile.VmSize = "<newVMsize>" Update-AzVM -VM $vm -ResourceGroupName $resourceGroup ``` **Use PowerShell to resize a VM not in an availability set.** This Cloud shell PowerShell script initializes the variables `$resourceGroup`, `$vm`, and `$size` with the resource group name, VM name, and desired VM size respectively. It then retrieves the VM object from Azure using the `Get-AzVM` cmdlet. The script modifies the `VmSize` property of the VM's hardware profile to the desired size. Finally, it applies these changes to the VM in Azure using the `Update-AzVM` cmdlet. ```azurepowershell-interactive # Set variables $resourceGroup = 'myResourceGroup' $vmName = 'myVM' $size = 'Standard_DS3_v2' # Get the VM $vm = Get-AzVM -ResourceGroupName $resourceGroup -Name $vmName # Change the VM size $vm.HardwareProfile.VmSize = $size # Update the VM Update-AzVM -ResourceGroupName $resourceGroup -VM $vm ``` As an alternative to running the script in Azure Cloud Shell, you can also execute it locally on your machine. This local version of the PowerShell script includes additional steps to import the Azure module and authenticate your Azure account. > [!NOTE] > The local PowerShell may require the VM to restart to take effect. ```powershell # Import the Azure module Import-Module Az # Login to your Azure account Connect-AzAccount # Set variables $resourceGroup = 'myResourceGroup' $vmName = 'myVM' $size = 'Standard_DS3_v2' # Select the subscription Select-AzSubscription -SubscriptionId '<subscriptionID>' # Get the VM $vm = Get-AzVM -ResourceGroupName $resourceGroup -Name $vmName # Change the VM size $vm.HardwareProfile.VmSize = $size # Update the VM Update-AzVM -ResourceGroupName $resourceGroup -VM $vm ``` **Use PowerShell to resize a VM in an availability set** If the new size for a VM in an availability set isn't available on the hardware cluster currently hosting the VM, then you need to deallocate all VMs in the availability set to resize the VM. You also might need to update the size of other VMs in the availability set after one VM has been resized. To resize a VM in an availability set, run the below script. This script sets the variables `$resourceGroup`, `$vmName`, `$newVmSize`, and `$availabilitySetName`. It then checks if the desired VM size is available by using `Get-AzVMSize` and checking if the output contains the desired size. If the desired size isn't available, the script deallocates all VMs in the availability set, resizes them, and starts them again. If the desired size is available, the script resizes the VM. Replace the values of `$resourceGroup`, `$vmName`, `$newVmSize`, and `$availabilitySetName` with your own. ```azurepowershell-interactive # Set variables $resourceGroup = "myResourceGroup" $vmName = "myVM" $newVmSize = "<newVmSize>" $availabilitySetName = "<availabilitySetName>" # Check if the desired VM size is available $availableSizes = Get-AzVMSize ` -ResourceGroupName $resourceGroup ` -VMName $vmName | Select-Object -ExpandProperty Name if ($availableSizes -notcontains $newVmSize) { # Deallocate all VMs in the availability set $as = Get-AzAvailabilitySet ` -ResourceGroupName $resourceGroup ` -Name $availabilitySetName $virtualMachines = $as.VirtualMachinesReferences | Get-AzResource | Get-AzVM $virtualMachines | Stop-AzVM -Force -NoWait # Resize and restart the VMs in the availability set $virtualMachines | Foreach-Object { $_.HardwareProfile.VmSize = $newVmSize } $virtualMachines | Update-AzVM $virtualMachines | Start-AzVM exit } # Resize the VM $vm = Get-AzVM ` -ResourceGroupName $resourceGroup ` -VMName $vmName $vm.HardwareProfile.VmSize = $newVmSize Update-AzVM ` -VM $vm ` -ResourceGroupName $resourceGroup ``` ### [CLI](#tab/cli) To resize a VM, you need the latest [Azure CLI](/cli/azure/install-az-cli2) installed and you need to be signed into your Azure account using [az sign-in](/cli/azure/reference-index). The below script checks if the desired VM size is available before resizing. If the desired size isn't available, the script exits with an error message. If the desired size is available, the script deallocates the VM, resizes it, and starts it again. Replace the values of `resourceGroup`, `vm`, and `size` with your own. ```azurecli-interactive # Set variables resourceGroup=myResourceGroup vm=myVM size=Standard_DS3_v2 # Check if the desired VM size is available if ! az vm list-vm-resize-options --resource-group $resourceGroup --name $vm --query "[].name" | grep -q $size; then echo "The desired VM size is not available." exit 1 fi # Deallocate the VM az vm deallocate --resource-group $resourceGroup --name $vm # Resize the VM az vm resize --resource-group $resourceGroup --name $vm --size $size # Start the VM az vm start --resource-group $resourceGroup --name $vm ``` **Use Azure CLI to resize a VM in an availability set.** The below script sets the variables `resourceGroup`, `vm`, and `size`. It then checks if the desired VM size is available by using `az vm list-vm-resize-options` and checking if the output contains the desired size. If the desired size isn't available, the script exits with an error message. If the desired size is available, the script deallocates the VM, resizes it, and starts it again. Replace the values of `resourceGroup`, `vm`, and `size` with your own. ```azurecli-interactive # Set variables resourceGroup="myResourceGroup" vmName="myVM" newVmSize="<newVmSize>" availabilitySetName="<availabilitySetName>" # Check if the desired VM size is available availableSizes=$(az vm list-vm-resize-options \ --resource-group $resourceGroup \ --name $vmName \ --query "[].name" \ --output tsv) if [[ ! $availableSizes =~ $newVmSize ]]; then # Deallocate all VMs in the availability set vmIds=$(az vmss list-instances \ --resource-group $resourceGroup \ --name $availabilitySetName \ --query "[].instanceId" \ --output tsv) az vm deallocate \ --ids $vmIds \ --no-wait # Resize and restart the VMs in the availability set az vmss update \ --resource-group $resourceGroup \ --name $availabilitySetName \ --set virtualMachineProfile.hardwareProfile.vmSize=$newVmSize az vmss start \ --resource-group $resourceGroup \ --name $availabilitySetName \ --instance-ids $vmIds exit fi # Resize the VM az vm resize \ --resource-group $resourceGroup \ --name $vmName \ --size $newVmSize ``` ### [Terraform](#tab/terraform) To resize your VM in Terraform code, you modify the `size` parameter in the `azurerm_linux_virtual_machine` or `azurerm_windows_virtual_machine` resource blocks to the desired size and run `terraform plan -out main.tfplan` to see the VM size change that will be made. Then run `terraform apply main.tfplan` to apply the changes to resize the VM. This Terraform example modifies the size of an existing virtual machine when you're using the state file that created the original virtual machine. For the full Terraform code, see the [Windows Terraform quickstart](../windows/quick-create-terraform.md). :::code language="Terraform" source="~/terraform_samples/quickstart/101-windows-vm-with-iis-server/main.tf" range="91-117" highlight="8"::: --- ## Next steps - For more scalability, run multiple VM instances and scale out. - For more SKU selection information, see [Sizes for virtual machines in Azure](../sizes.md). - To determine VM sizes by workload type, OS and software, or deployment region, see [Azure VM Selector](https://azure.microsoft.com/pricing/vm-selector/). - For more information on Virtual Machine Scale Sets sizes, see [Automatically scale machines in a VMSS](../../virtual-machine-scale-sets/tutorial-autoscale-powershell.md). - For more cost management planning information, see the [Plan and manage your Azure costs](/training/modules/plan-manage-azure-costs/1-introduction) module.