VMs not responding after reboot following Windows update installations

Question

We are a small company with just a few servers, so at this point we do all Windows updates manually. Last night I installed updates on all my servers within one resource group and after rebooting they were no longer accessible. I had to reset the NIC on each machine using the instructions here: https://learn.microsoft.com/en-us/troubleshoot/azure/virtual-machines/reset-network-interface

Sometimes it took more than one try for it to work (actually with one server it took about an hour and 8 - 10 tries). Has anyone else experienced this? I have another server in a different resource group (but still in US East) that did not have these same issues.

What I'm looking for is an underlying reason as to why this might have happened. Did something change on in the Azure underlying structure that might have caused this? Where would I find information about any changes that might have affected this.

Before I did the NIC reset process, I did try multiple other options, including restoring the server, stopping then restarting the VM, redeploying the server, and none of those options worked.

I have 6 total servers that had this issue. All are Server 2019 Datacenter VMs. One is a web server, 4 are app servers, and one is a SQL server. They have different sizes so I'm fairly certain it has nothing to do with VM size.

Edited to add: for clarity sake, after the reboot I was unable to ping, I was unable to RDP, there was no network connectivity at all. Within the Azure environment I was getting errors regarding the VM agent. Tried to reinstall this on one of the servers and it had no effect either.

Any assistance, guidance on where to start looking for underlying issues, or other information would be greatly appreciated!

Answer 1

Hello,

I think that there was a Microsoft fix in the OOB patch KB5010794:

https://support.microsoft.com/en-us/topic/kb5010794-out-of-band-update-for-windows-8-1-and-windows-server-2012-r2-january-17-2022-a92500fb-f227-400e-b70e-f7dd50386fd3

Here some additional troubleshooting steps:

Azure VM startup is stuck at Windows update
https://learn.microsoft.com/en-us/troubleshoot/azure/virtual-machines/troubleshoot-stuck-updating-boot-error

and more specific ones:

VM is unresponsive with "C01A001D" error after applying Windows Update
https://learn.microsoft.com/en-us/troubleshoot/azure/virtual-machines/unresponsive-vm-apply-windows-update

Hope this helps with your query!

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