Azure virtual machine extensions and features
Extensions are small applications that provide post-deployment configuration and automation on Azure virtual machines (VMs). The Azure platform hosts many extensions covering VM configuration, monitoring, security, and utility applications. Publishers take an application, wrap it into an extension, and simplify the installation. All you need to do is provide mandatory parameters.
View available extensions
You can view available extensions for a VM in the Azure portal.
- In the portal, go to the Overview page for a VM.
- Under Settings, select Extensions + Applications.
The list of available extensions are displayed. To see the complete list of extensions, see Discovering VM Extensions for Linux and Discovering VM Extensions for Windows.
Install and use extensions
Azure VM extensions can be managed by using the Azure CLI, PowerShell, Azure Resource Manager (ARM) templates, and the Azure portal.
- From the Extensions + Applications for the VM, on the Extensions tab, select + Add.
- Locate the Custom Script Extension option. Select the extension option, then select Next.
You can then pass in a command or script to run the extension.
For more information, see Linux Custom Script Extension and Windows Custom Script Extension.
Check for prerequisites
Some individual VM extension applications might have their own environmental prerequisites, such as access to an endpoint. Each extension has an article that explains any prerequisites, including which operating systems are supported.
Manage extension application lifecycle
You don't need to connect to a VM directly to install or delete an extension. The Azure extension lifecycle is managed outside of the VM and integrated into the Azure platform.
Troubleshoot extensions
If you're looking for general troubleshooting steps for Windows VM extensions, refer to Troubleshooting Azure Windows VM extension failures.
Otherwise, specific troubleshooting information for each extension can be found in the Troubleshoot and support section in the overview for the extension. Here's a list of the troubleshooting information available:
| Namespace | Troubleshooting |
|---|---|
| microsoft.azure.security.azurediskencryptionforlinux | Azure Disk Encryption for Linux |
| microsoft.azure.security.azurediskencryption | Azure Disk Encryption for Windows |
| microsoft.compute.customscriptextension | Custom Script for Windows |
| microsoft.ostcextensions.customscriptforlinux | |
| microsoft.powershell.dsc | Desired State Configuration for Windows |
| microsoft.azure.security.iaasantimalware | Antimalware Extension for Windows |
| microsoft.enterprisecloud.monitoring.omsagentforlinux | Azure Monitor for Linux |
| microsoft.enterprisecloud.monitoring.microsoftmonitoringagent | Azure Monitor for Windows |
| vmaccessforlinux.microsoft.ostcextensions | VMAccess for Linux |
| microsoft.recoveryservices.vmsnapshot | Snapshot for Linux |
| microsoft.recoveryservices.vmsnapshot | Snapshot for Windows |
Next steps
- For more information about how the Linux Agent and extensions work, see Azure VM extensions and features for Linux.
- For more information about how the Windows Guest Agent and extensions work, see Azure VM extensions and features for Windows.
- To install the Linux Agent, see Azure Linux Virtual Machine Agent overview.
- To install the Windows Guest Agent, see Azure Windows Virtual Machine Agent overview.