Azure Windows VM Agent overview

Artikkeli
10/07/2024

The Microsoft Azure Windows VM Agent is a secure, lightweight process that manages virtual machine (VM) interaction with the Azure fabric controller. The Azure Windows VM Agent has a primary role in enabling and executing Azure virtual machine extensions. VM extensions enable post-deployment configuration of VMs, such as installing and configuring software. VM extensions also enable recovery features such as resetting the administrative password of a VM. Without the Azure Windows VM Agent, you can't run VM extensions.

This article describes how to install and detect the Azure Windows VM Agent.

Prerequisites

The Azure Windows VM Agent supports the x64 architecture for these Windows operating systems:

Windows 10
Windows 11
Windows Server 2008 SP2
Windows Server 2008 R2
Windows Server 2012
Windows Server 2012 R2
Windows Server 2016
Windows Server 2016 Core
Windows Server 2019
Windows Server 2019 Core
Windows Server 2022
Windows Server 2022 Core

Important

The Azure Windows VM Agent needs at least Windows Server 2008 SP2 (64-bit) to run, with the .NET Framework 4.0. See Minimum version support for virtual machine agents in Azure.
Ensure that your VM has access to IP address 168.63.129.16. For more information, see What is IP address 168.63.129.16?.
Ensure that DHCP is enabled inside the guest VM. This is required to get the host or fabric address from DHCP for the Azure Windows VM Agent and extensions to work. If you need a static private IP address, you should configure it through the Azure portal or PowerShell, and make sure the DHCP option inside the VM is enabled. Learn more about setting up a static IP address by using PowerShell.
Running the Azure Windows VM Agent in a nested virtualization VM might lead to unpredictable behavior, so it's not supported in that dev/test scenario.

Install the Azure Windows VM Agent

Azure Marketplace image

The Azure Windows VM Agent is installed by default on any Windows VM deployed from an Azure Marketplace image. When you deploy an Azure Marketplace image from the Azure portal, PowerShell, the Azure CLI, or an Azure Resource Manager template, the Azure Windows VM Agent is also installed.

The Azure Windows VM Agent package has two parts:

Azure Windows Provisioning Agent (PA)
Azure Windows Guest Agent (WinGA)

To boot a VM, you must have the PA installed on the VM. However, the WinGA does not need to be installed. At VM deploy time, you can select not to install the WinGA. The following example shows how to select the provisionVmAgent option with an Azure Resource Manager template:

{
	"resources": [{
		"name": ["parameters('virtualMachineName')"],
		"type": "Microsoft.Compute/virtualMachines",
		"apiVersion": "2016-04-30-preview",
		"location": ["parameters('location')"],
		"dependsOn": ["[concat('Microsoft.Network/networkInterfaces/', parameters('networkInterfaceName'))]"],
		"properties": {
			"osProfile": {
				"computerName": ["parameters('virtualMachineName')"],
				"adminUsername": ["parameters('adminUsername')"],
				"adminPassword": ["parameters('adminPassword')"],
				"windowsConfiguration": {
					"provisionVmAgent": "false"
				}
			}
		}
	}]
}

If you don't have the agents installed, you can't use some Azure services, such as Azure Backup or Azure Security. These services require an extension to be installed. If you deploy a VM without the WinGA, you can install the latest version of the agent later.

Manual installation

You can manually install the Azure Windows VM Agent by using a Windows Installer package. Manual installation might be necessary when you create a custom VM image that's deployed to Azure.

To manually install the Azure Windows VM Agent, download the installer and select the latest release. You can also search for a specific version in the GitHub page for Azure Windows VM Agent releases. The Azure Windows VM Agent is supported on Windows Server 2008 (64 bit) and later.

Note

If a VM was created from a custom or Marketplace image without ProvisionVMAgent enabled, then it is important to update the AllowExtensionOperations to true after you manually install the Azure Windows VM Agent.
This is NOT required if the VM was created from a specialized disk. For example, if the VM was created directly from an existing disk.

$vm = Get-AzVM -Name <VM Name> -ResourceGroupName <Resource Group Name>
$vm.OSProfile.AllowExtensionOperations = $true
$vm | Update-AzVM

Detect the Azure Windows VM Agent

PowerShell

You can use the Azure Resource Manager PowerShell module to get information about Azure VMs. To see information about a VM, such as the provisioning state for the Azure Windows VM Agent, use Get-AzVM:

Get-AzVM

The following condensed example output shows the ProvisionVMAgent property nested inside OSProfile. You can use this property to determine if the VM agent has been deployed to the VM.

OSProfile                  :
  ComputerName             : myVM
  AdminUsername            : myUserName
  WindowsConfiguration     :
    ProvisionVMAgent       : True
    EnableAutomaticUpdates : True

Use the following script to return a concise list of VM names (running Windows OS) and the state of the Azure Windows VM Agent:

$vms = Get-AzVM

foreach ($vm in $vms) {
    $agent = $vm | Select -ExpandProperty OSProfile | Select -ExpandProperty Windowsconfiguration | Select ProvisionVMAgent
    Write-Host $vm.Name $agent.ProvisionVMAgent
}

Use the following script to return a concise list of VM names (running Linux OS) and the state of the Azure Windows VM Agent:

$vms = Get-AzVM

foreach ($vm in $vms) {
    $agent = $vm | Select -ExpandProperty OSProfile | Select -ExpandProperty Linuxconfiguration | Select ProvisionVMAgent
    Write-Host $vm.Name $agent.ProvisionVMAgent
}

Manual detection

When you're logged in to a Windows VM, you can use Task Manager to examine running processes. To check for the Azure Windows VM Agent, open Task Manager, select the Details tab, and look for a process named WindowsAzureGuestAgent.exe. The presence of this process indicates that the VM agent is installed.

Upgrade the Azure Windows VM Agent

The Azure Windows VM Agent for Windows is automatically upgraded on images deployed from Azure Marketplace. The new versions are stored in Azure Storage, so ensure that you don't have firewalls blocking access. As new VMs are deployed to Azure, they receive the latest VM agent at VM provision time. If you installed the agent manually or are deploying custom VM images, you need to manually update to include the new VM agent at image creation time.

Azure Windows Guest Agent automatic log collection

The Azure Windows Guest Agent has a feature to automatically collect some logs. The CollectGuestLogs.exe process controls this feature. It exists for both platform as a service (PaaS) cloud services and infrastructure as a service (IaaS) VMs. Its goal is to quickly and automatically collect diagnostics logs from a VM, so they can be used for offline analysis.

The collected logs are event logs, OS logs, Azure logs, and some registry keys. The agent produces a ZIP file that's transferred to the VM's host. Engineering teams and support professionals can then use this ZIP file to investigate issues on the request of the customer who owns the VM.

Azure Windows Guest Agent and OSProfile certificates

The Azure Windows VM Agent installs the certificates referenced in the OSProfile value of a VM or a virtual machine scale set. If you manually remove these certificates from the Microsoft Management Console (MMC) Certificates snap-in inside the guest VM, the Azure Windows Guest Agent will add them back. To permanently remove a certificate, you have to remove it from OSProfile, and then remove it from within the guest operating system.

For a virtual machine, use Remove-AzVMSecret to remove certificates from OSProfile.

For more information on certificates for virtual machine scale sets, see Azure Virtual Machine Scale Sets - How do I remove deprecated certificates?.

Next steps

For more information about VM extensions, see Azure virtual machine extensions and features.

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