Our windows server stuck at restart screen after update installation

Question

I have installed cumulative update (January 2023) on our Windows Server 2016 Datacenter

Have checked in Boot diagnostics, update installed and it shows below.

Installing Windows 100% Don't turn off your PC. This will take a while Your PC will restart several times

Later the server was stuck on restart screen. I know For Windows Update, if the size of the updates was large, the operating system needs more time to reconfigure the changes. We have only installed one KB.

The server was stuck on restart screen more than 30 minute. We cannot keep our production vm in that stage. So i have stopped and started vm from Azure portal and vm booted fine.

1. Not sure what was the cause of this why server is stuck on restart screen? What is the reason?
2. What is the mitigation of such issues?
3. What logs we can check for cause?

Answer 1

Hi. Thank you for your question and reaching out. I’d be more than happy to help you with your query

If the server was stuck on the restart screen for more than 30 minutes after installing a cumulative update, it could indicate a problem with the update itself or with the installation process. The first step would be to check the Windows Event logs for any error messages or warnings related to the update or the restart process.

You can also try running the Windows Update troubleshooter to resolve any issues with the update process. If that doesn't help, you may need to manually uninstall the update and try reinstalling it again.

If the reply was helpful, please don’t forget to upvote or accept as answer, thank you.

Answer 2

Hello, @sethian !

What should I do if my Windows VM is stuck on the restart screen after an update?

There are a lot of possible causes and solutions as well as documentation that goes through what you can do from a mitigation and logging standpoint. I'm going to do my best to provide a quick overview as well as a good starting point and then walk through troubleshooting.

• How long should I wait for Windows Update on my VM? The recommendation is to wait 8 hours depending on the number of updates that are getting installed or rolled back (source).
• What happens if I stop the update process before it is done? Depending on the number of updates/changes and the VM size, the process may take a long time. If the process is stopped, it's possible for the OS to become corrupt. Only interrupt the process if it's taking excessively long (source).
• How can I minimize impact in a production environment? If enabled, automatic VM guest patching allows critical and security patches to be downloaded and applied automatically to your VM for security and stability. Patches are installed only during off-peak hours for the VM, depending on the time zone of the VM. Using high availability either with VMs in an availability set, an availability zone, geo-paired regions, and VM scale sets allows you to maintain the availability of your VM (source 1 and source 2).
• What causes restarting issues on my VM? There may have been an error with an update but it's also possible for a third-party service that is flagged as critical cannot be started, there may be file system corruption, or a number of other causes which can be determined by looking at logs (below) (source).
• What logs should I collect and how do I collect them? You can collect the following logs to get a better idea of what has happened: a process memory dump (instructions) and an OS memory dump (memory.dmp is located on the attached OS disk under Windows - instructions). If the OS memory dump reveals an issue, the recommendation is to submit a support ticket with the dump file.
• What troubleshooting steps can I take? Depending on the cause, you can attach the OS disk to a recovery VM (this involves taking a snapshot of the disk and attaching it to a recovery VM - instructions), remove the update that caused the problem (instructions), address the third-party service or roll back the VM (instructions), or start your Windows VM with the last known good configuration (instructions).

I know that's a lot to go through but hopefully this is helpful. I'm going to include a list of documentation resources below for additional reading:

• Azure Windows VM shutdown is stuck on "Restarting", "Shutting Down", or "Stopping services"
• VM startup is stuck on "Getting Windows ready. Don't turn off your computer" in Azure
• Azure VM startup is stuck at Windows update
• Windows reboot loop on an Azure VM
• Understand a system reboot for Azure VM
• How to start Azure Windows VM with Last Known Good Configuration
• Automatic VM guest patching for Azure VMs
• Availability options for Azure Virtual Machines
• Azure Metadata Service: Scheduled Events for Windows VMs