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High CPU usage for WMI and svchost

    Question

  • Hello, I have a brand new server with Windows 2012 pre-installed. I setup the HyperV role and there are a couple virtual machines running on it. I noticed that the CPU usage is constantly at about 30% with the main culprits being svchost and WMI.

    Restarting the WMI service makes the CPU usage go to normal, but starts up again in about 10 to 15 minutes. Even if the HyperV services are stopped and no VM's are running this is still the case. It's also the case with all non MS services stopped.

    All the latest Server 2012 updates have been applied.

    Here is a sample of the xperf data for about 30 seconds while this is happening. Can anyone tell me what is happening? I am having a hard time interpreting the data.

    http://sdrv.ms/108p7zn

    Thankyou



    • Edited by pipnz Wednesday, March 06, 2013 10:48 PM
    Wednesday, March 06, 2013 10:46 PM

All replies

  • Just a couple of points to remember about what you are seeing:

    1. If you are viewing generic "CPU Usage" counters, like task manager, you are seeing the parent partition usage, not total.  
    2. WMI is the management interface for Hyper-V.  Hyper-V is running underneath Server 2012 (the parent partition) and all of the interactions are performed through WMI

    This doesn't necessarily solve your issue, but it may help you understand what you are looking at.  Open Performance Monitor and monitor some of the Hyper-V logical processor counters to see how the physical CPU performance is.



    C Shane Cribbs
    http://www.georgiatechnologies.com

    Thursday, March 07, 2013 12:38 AM
  • Thanks Shane, I have watched performance monitor too, and have noticed that 3 of the 4 cores are being used at around 30% load. It isnt one core being pegged at 100%. The issue I am having is interpreting the xperf data to see what exactly is causing the issue. Were you able to have a look?

    Thankyou

    Thursday, March 07, 2013 10:14 PM
  • Sorry, but honestly I've never even attempted to figure out xperf data.  I would look at two additional counters on the physical computer: %DPC time and %interrupt time.  Are either of these two high?  They should both be pretty low, but %Interrupt Time should be the lowest.  IF %DPC is lower than %Interrupt, you have a driver issue.  Update your drivers.


    C Shane Cribbs
    http://www.georgiatechnologies.com

    Thursday, March 07, 2013 10:24 PM
  • What should I be looking at to isolate the cause of this issue?
    Monday, March 11, 2013 11:59 PM
  • Hi,

    I don’t think 30% CPU usage is high if you have a couple virtual machines running on it.

    For more troubleshooting information regarding high CPU usage, please refer to the following Microsoft TechNet blog:

    PRF: High CPU (SVCHOST.EXE)

    http://blogs.technet.com/b/askperf/archive/2009/04/10/prf-high-cpu-svchost-exe.aspx

    Using Netmon to figure out the source of high CPU in WMIprvse.exe

    http://blogs.msdn.com/b/ntdebugging/archive/2009/04/24/using-netmon-to-figure-out-the-source-of-high-cpu-in-wmiprvse-exe.aspx

    Regards,


    Arthur Li

    TechNet Community Support

    Tuesday, March 12, 2013 5:11 AM
  • Thankyou Arthur, but this is also when no Virtual Machines are running and the machine is at idle. I will look into those documents and report back.
    Tuesday, March 12, 2013 5:39 AM
  • There is no network activity from any monitoring tools, the only current network activity is broadcast traffic, so netmon comes up with nothing useful.

    I have attached the xperf logs previously. Looking at the perfmon traces I am not seeing anything obvious. Has anyone been able to look at the xperf data?

    Thursday, March 21, 2013 9:20 PM