InfiniBand Driver Extension for Windows

This extension installs InfiniBand ND drivers (for non-SR-IOV enabled) and OFED drivers (for SR-IOV-enabled) ('r' sizes) H-series and N-series VMs running Windows. Depending on the VM family, the extension installs the appropriate drivers for the Connect-X NIC.

An extension is also available to install InfiniBand drivers for Linux VMs.


Operating system

This extension supports the following OS distros, depending on driver support for specific OS version. Note the appropriate InfiniBand NIC for the H and N-series VM sizes of interest.

Distribution InfiniBand NIC drivers
Windows 10 CX5, CX6
Windows Server 2019 CX5, CX6
Windows Server 2016 CX5, CX6
Windows Server 2012 R2 CX5, CX6

For latest list of supported OS and driver versions, refer to resources.json

Internet connectivity

The Microsoft Azure Extension for InfiniBand Drivers requires that the target VM is connected to and has access to the internet.

Extension schema

The following JSON shows the schema for the extension.

  "name": "<myExtensionName>",
  "type": "extensions",
  "apiVersion": "2015-06-15",
  "location": "<location>",
  "dependsOn": [
    "[concat('Microsoft.Compute/virtualMachines/', <myVM>)]"
  "properties": {
    "publisher": "Microsoft.HpcCompute",
    "type": "InfiniBandDriverWindows",
    "typeHandlerVersion": "1.5",
    "autoUpgradeMinorVersion": true,
    "settings": {


Name Value / Example Data Type
apiVersion 2015-06-15 date
publisher Microsoft.HpcCompute string
type InfiniBandDriverWindows string
typeHandlerVersion 1.5 int


Azure Resource Manager Template

Azure VM extensions can be deployed with Azure Resource Manager templates. Templates are ideal when deploying one or more virtual machines that require post deployment configuration.

The JSON configuration for a virtual machine extension can be nested inside the virtual machine resource, or placed at the root or top level of a Resource Manager JSON template. The placement of the JSON configuration affects the value of the resource name and type. For more information, see Set name and type for child resources.

The following example assumes the extension is nested inside the virtual machine resource. When nesting the extension resource, the JSON is placed in the "resources": [] object of the virtual machine.

  "name": "myExtensionName",
  "type": "extensions",
  "location": "[resourceGroup().location]",
  "apiVersion": "2015-06-15",
  "dependsOn": [
    "[concat('Microsoft.Compute/virtualMachines/', myVM)]"
  "properties": {
    "publisher": "Microsoft.HpcCompute",
    "type": "InfiniBandDriverWindows",
    "typeHandlerVersion": "1.5",
    "autoUpgradeMinorVersion": true,
    "settings": {


    -ResourceGroupName "myResourceGroup" `
    -VMName "myVM" `
    -Location "southcentralus" `
    -Publisher "Microsoft.HpcCompute" `
    -ExtensionName "InfiniBandDriverWindows" `
    -ExtensionType "InfiniBandDriverWindows" `
    -TypeHandlerVersion 1.5 `
    -SettingString '{ `

Azure CLI

az vm extension set \
  --resource-group myResourceGroup \
  --vm-name myVM \
  --name InfiniBandDriverWindows \
  --publisher Microsoft.HpcCompute \
  --version 1.5 

Add extension to a Virtual Machine Scale Set

The following example installs the latest version 1.5 InfiniBandDriverWindows extension on all RDMA-capable VMs in an existing virtual machine scale set named myVMSS deployed in the resource group named myResourceGroup:

$VMSS = Get-AzVmss -ResourceGroupName "myResourceGroup" -VMScaleSetName "myVMSS"
Add-AzVmssExtension -VirtualMachineScaleSet $VMSS -Name "InfiniBandDriverWindows" -Publisher "Microsoft.HpcCompute" -Type "InfiniBandDriverWindows" -TypeHandlerVersion "1.5"
Update-AzVmss -ResourceGroupName "myResourceGroup" -VMScaleSetName "MyVMSS" -VirtualMachineScaleSet $VMSS
Update-AzVmssInstance -ResourceGroupName "myResourceGroup" -VMScaleSetName "myVMSS" -InstanceId "*"

Troubleshoot and support


Data about the state of extension deployments can be retrieved from the Azure portal, and by using Azure PowerShell and Azure CLI. To see the deployment state of extensions for a given VM, run the following command.

Get-AzVMExtension -ResourceGroupName myResourceGroup -VMName myVM -Name myExtensionName
az vm extension list --resource-group myResourceGroup --vm-name myVM -o table

Extension execution output is logged to the following file. Refer to this file to track the status of the installation as well as for troubleshooting any failures.


Exit codes

The following table describes the meaning and recommended action based on the exit codes of the extension installation process.

Error Code Meaning Possible Action
0 Operation successful
3010 Operation successful. Reboot required.
100 Operation not supported or could not be completed. Possible causes: PowerShell version not supported, VM size is not an InfiniBand-enabled VM, Failure downloading data. Check the log files to determine cause of error.
240, 840 Operation timeout. Retry operation.
-1 Exception occurred. Check the log files to determine cause of exception.


If you need more help at any point in this article, you can contact the Azure experts on the MSDN Azure and Stack Overflow forums. Alternatively, you can file a support incident through the Azure support site. For information about using Azure Support, read the Microsoft Azure support FAQ.

Next steps

For more information about InfiniBand-enabled ('r' sizes), see H-series and N-series VMs.