How to reduce high CPU utilization on Windows Server VM in Hyper-V environment?

Question

Question: I am facing an issue with my Windows Server VM running on Hyper-V on my Windows 11 PC. My VM is currently running Active Directory Services, DHCP, and DNS, but I noticed that its CPU utilization is at 98.97% causing the local server tile's performance tab to show red. My Windows 11 Host and VM's task manager show CPU utilization between 0 to 3%. I have allocated 4vCPUs and 8GB of RAM to the VM, and my PC specs are a B550M motherboard, 32GB of RAM with a 5600x, and a 1TB NVME SSD. Can you provide any guidance on how to troubleshoot and resolve this issue? Thank you.

Answer 1

Hello Cory,

Thank you for your question and for reaching out with your question today.

High CPU utilization on a Windows Server VM running Active Directory Services, DHCP, and DNS can be caused by various factors. Here are some steps you can take to troubleshoot and resolve the issue:

1. Resource Allocation: First, let's ensure that the VM has enough resources allocated to handle the services you're running. You mentioned that you have allocated 4 vCPUs and 8GB of RAM to the VM, which should generally be sufficient for these services. However, if your VM is under heavy load, you may consider increasing the vCPUs and RAM allocation.
2. Check Resource Monitor: Use the Resource Monitor on the Windows Server VM to identify which processes or services are consuming the most CPU resources. It will give you more detailed information than the Task Manager. Look for any specific processes that are causing the high CPU utilization.
3. Performance Monitor: Use Performance Monitor (perfmon) on the Windows Server VM to monitor various performance counters over time. Look for spikes or consistently high CPU usage. You can monitor specific counters related to Active Directory, DHCP, and DNS to identify any issues.
4. Task Manager on VM: Open the Task Manager on the VM and check the "Processes" tab to see which specific processes are using the CPU. Sort the processes by CPU usage to identify the top CPU consumers.
5. Anti-Virus: If you have an antivirus software installed on the VM, it could be scanning the files and causing high CPU usage. Temporarily disable the antivirus to see if it makes a difference.
6. Check Event Viewer: Check the Event Viewer on the Windows Server VM for any error or warning messages related to CPU usage, services, or applications. These logs may provide clues about what is causing the high CPU utilization.
7. Update VM Integration Services: Ensure that you have the latest version of Hyper-V Integration Services installed on the Windows Server VM. This helps improve the performance and compatibility of the VM with the host.
8. Check for Malware: Perform a malware scan on the Windows Server VM to rule out any malicious software that might be causing high CPU usage.
9. Update Drivers: Ensure that the drivers on both the Windows Server VM and the Windows 11 host are up to date, especially for the motherboard and network adapters.
10. Consider Separate VMs: If the CPU usage is still high and you have enough resources on your host, consider splitting the services into separate VMs. Running Active Directory, DHCP, and DNS on separate VMs can help isolate resource usage and improve performance.
11. Check for VM Configuration Issues: Verify that there are no configuration issues in the VM's settings, such as incorrect resource limits, CPU compatibility settings, or power settings.

By following these troubleshooting steps, you should be able to identify the cause of the high CPU utilization and take appropriate actions to resolve the issue. Remember to make changes one at a time and monitor the impact to determine the effectiveness of each step.

I used AI provided by ChatGPT to formulate part of this response. I have verified that the information is accurate before sharing it with you.

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