Azure VM restarts randomly and crashes

Question

Hello, I noticed random restarts of my bigger azure VMs (4 and 8 cores) on Windows Server 2016. It wasn't happening before. VM is created from image, software is installed (always the same) and after a few days, one or two weeks VM restarts. It has running status after manual starting it from the portal but properties like computer name or host are unavailable. RDP stopped working.
From the logs I can only see messages from Health Event Updated:
"channels": "Admin, Operation",
"properties": {
"title": "Unknown",
"details": "Unknown",
"currentHealthStatus": "Unavailable",
"previousHealthStatus": "Available",
"type": "Downtime",
"cause": "Unknown"
},

and

"properties": {
"title": "Reboot initiated from inside the machine",
"details": "A reboot was triggered from inside the virtual machine. This could be due to a virtual machine operating system failure or as requested by an authorized user or process. The virtual machine will be back online after the reboot completes.",
"currentHealthStatus": "Unavailable",
"previousHealthStatus": "Unavailable",
"type": "Downtime",
"cause": "UserInitiated"
},

Since then VM is not working. The same VMs created a few months ago do work fine actually.

How these kind of issues could happen?
I don't know how to fix that. Removing VM with its disk from the portal and creating again results in the same issue after some time. This is really frustrating.

Thanks!

Answer 1

Hi there,

I am sorry for not being active lately...

It turned out that the problem was with one cumulative update. An update caused that VM was not able to boot up.
I reproduced that issue on the new VM with image from the marketplace in October. One month later VM was not able to boot up after installing November cumulative update. It happened on an E series VM with intel CPUs. Others series seem to be fine for me.

Cheers