Virtual server shutdown

Question

Hello, the virtual machine I created on azure restarts every now and then, what could be the reason?

Answer 1

Hello, @ATLAS !

If this is an every now and then occurrence, then I would start by checking the system and application logs for Windows VMs, and the serial logs for Linux VMs as it could be a resource limit or application issue that is causing a crash.

Why did my VM reboot unexpectedly?
There are a number of reasons why your VM might reboot (as well as a quick reminder that configuring your VM for high availability is the best way to protect against reboots and downtime). There are some resources in the documentation that cover troubleshooting in more detail:

Understand a system reboot for Azure VM

Get more information:

• Check resource health information: Azure Resource Health is a service that exposes the health of individual Azure resources and provides actionable guidance for troubleshooting problems.
• Check the activity log: Resource Health alerts are sent based on the activity Log information. Note that VM downtimes won't show in the activity log when a VM is created or migrated to a new host, if the VM availability state changes from Available to Unavailable and back within 35 seconds, or if the VM health changes from a state to Unknown and back to the original state as this is filtered out.
• Check the Azure Service Health Dashboard (link) to see if something has affected VMs in your datacenter (rare).
• Diagnose VM restarts using the Diagnose and Solve blade on the VM blade to run additional diagnostics.

Causes - Maintenance:

• Planned maintenance sometimes requires a reboot. You can read more about planned maintenance for VMs as well as how to schedule planned maintenance.
• Memory-preserving updates should not have an impact on users however the VM will enter the paused state and then be resumed typically within 30 seconds.
• User-initiated reboot/shutdown is in the activity log if it is initiated from Azure and in the system logs if it's initiated in the OS.
• Microsoft Defender for Cloud and Windows will apply updates as configured.

Causes - Infrastructure:

• Host server faults can cause a reboot as the host server attempts a recovery (usually caused by hardware failure).
• Auto-recovery is rare but needed if a faulty host needs to be taken out of rotation and the VMs are automatically relocated to a different, healthy host server.
• VM crashes can be caused by the VM itself if the workload or role triggers a bug check.
• Storage-related forced shutdowns will happen if the availability or connectivity is affected for more than 120 seconds.
• Contact support by creating a support request if you've gone through everything and still are unable to determine why the VM is restarting.

Hopefully this will determine why your VM is restarting but if it doesn't, please let us know in the comments so we can continue to troubleshoot and investigate this.

Additional Reading:

• Understand a system reboot for Azure VM
• Troubleshoot unexpected reboots of VMs with attached VHDs
• OS start-up – Computer restarted unexpectedly or encountered an unexpected error
• Windows reboot loop on an Azure VM
• Azure Windows VM shutdown is stuck on "Restarting", "Shutting Down", or "Stopping services"

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