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Tuesday, October 11, 2011

Issue Assign 2 Vcpu but shown as 1 Vcpu on Windows Server 2003 Virtual machine.


Weird experience.Probably 1 out of a million. I have done a lot of Windows Server 2003 Virtual Machine deployment but encountered a very weird scenario. Here is the scenario

  • Assign 2 vcpu to a Windows Server 2003 SP2 Guest operating system
  • When view from task manager, it only indicated 1 vcpu.
  • On Device manager, indicated 2 processor and ACPI Multiprocessor PC.
  • Go to command prompt and enter echo %number_of_processors% will give you result 1.
  • Reinstall SP2 but still failed
  • Uninstall Integration Services and Reinstall Integration Services but still failed.
  • Change to 4 vcpu but still shown 1.
  • Change on boot.ini to use 2 processor but still failed.
  • Hypervisor:- Windows Server 2008 R2 Enterprise Edition with SP1
  • Delete the VM Configuration and recreate but still failed.




1. Reinstall SP2

2. Uninstall IC. Restart the Server

3. Reinstall IC. Restart the Server

4. When view task manager, you will still see 1 processor.

5. Shutdown the Vm

6. Change the virtual cpu to 1.

7. Start the VM and wait the system detect a new hardware and prompt ask to restart.

8. Restart the VM. Once boot up. Shut down the VM

9. Change back to 2vcpu and start the VM

10. Wait for the system detect a new hardware and prompt ask to restart. If you view task manager, it will still indicate 1 processor.

11. Restart the VM

12. Once restart, the VM will have 2 processor when you view from task manager.

Quite weird but i suspect is due to SP2 which i have previously uninstall and reinstall SP2 process. 

Well, at least now it is work on my side for 2 VMs. Another 3 VMs on the same Hyper-V Host did not experience this issue. Weird!…