How to troubleshoot Azure IaaS VMs using the Azure Serial Console

When you issues on an Azure virtual machine (), you can connect to the VM by using the remote tools such as the serial console for Azure Virtual Machines, Run command, and many more. The Serial Console in the Azure portal provides access to a text-based console for Azure virtual machines (VMs) and virtual machine scale set instances. It is a great tool to troubleshoot Azure IaaS VMs if you lost access to the machine using RDP, SSH, or PowerShell remoting.

The Azure Serial Console works with Windows and Linux virtual machines. For Linux VMs, the serial connection connects to the ttys0 serial port of the or virtual machine scale set instance, providing access to it independent of the or operating system state. For Windows VMs, the serial connection connects to the COM1 serial port of the VM or virtual machine scale set instance, providing access to it independent of the or operating system state.

Prerequisites

To use the serial console, you have the following prerequisites.

To find more information check out Microsoft Docs.

Enable Serial Console functionality for Windows Server

In this blog post, I will quickly show you how you can enable the serial console for a , if you want to do it for a Linux VM, check out the following link.

Newer images on Azure haveSpecial Administration Console(SAC) enabled by default. SAC is supported on server versions of Windows but isn't available on client versions (for example, Windows 10, Windows 8, or Windows 7).

Enable EMS Run CommandEnable EMS Run Command

For older images (created before February 2018), you can automatically enable the serial console through the Azure portal's run command feature. In the Azure portal, selectRun command, then select the command namedEnableEMSfrom the list.

There is also an option to enable EMS manually.

Access the VM using the Azure serial console

To access the serial console, you simply go to the virtual machine in the Azure portal, and under Support + troubleshooting, you can find the serial console.

Azure Serial ConsoleAzure Serial Console

Now you can follow these steps:

  1. Enter “cmd” to create a new channel for the CMD instance
  2. Type “ch -si 1” to connect to the instance.
  3. Press Enter
  4. Enter your credentials to log in to the VM
  5. Now you can run CMD commands, and if you need PowerShell, you can also just start PowerShell by typing “PowerShell”.

Azure Serial Console PowerShell SessionAzure Serial Console PowerShell Session

Conclusion

The Azure Serial Console is a great way to troubleshoot or access configurations for Azure virtual machines. You can learn more about the Azure serial console here:

I hope this blog post was helpful. If you have any questions or comments, feel free to leave a comment.

 

This article was originally published by Microsoft's Entra (Azure AD) Blog. You can find the original article here.