Windows 2012 R2 File server CPU usage %100 for most of the work day

2018-09-28

Question

_{Friday, September 28, 2018 2:32 PM}

Hello,

We have a problem on our 2012 R2 File server VM, running on Esxi 6 data center (SSD cluster)
During the day peak time we get alerts high VM CPU usage, System process(Ntoskrnl) seems to be constant 100%, in the evening as people go home, server is back to normal (4 CPU, 8GB Ram, 2 NIC assigned to server, about 200 users), so there are correlations between, number of users loged having too many files open that server cannot handle but having a few hundred files open, cannot be the cause. Any idea?

All replies (4)

_{Monday, October 1, 2018 2:37 AM}

Hi Camci M

On server 2012, there's the related hotfix about such scenario. I haven't find the specific hotfix on server 2012R2. But you could still keep the the server 2012R2 install the latest updates.

https://support.microsoft.com/en-us/help/2830448/high-cpu-usage-on-a-windows-server-2012-based-server-when-many-client

And to find the root cause, we need to look inside the System process, you can use a tool like Process Explorer.
/en-us/sysinternals/downloads/process-explorer

Download and run it, then select the System process, right-click and select Properties.

This will show which file is using the excessive CPU usage, from which you can then attempt to diagnose it.

In addition, in your scenario, the server 2012R2 is the vm in Vmware. This is also could also be one big factor that affect performance of the server. Please also consult in Vmware side to make sure all the configuration are right.

Best Regards,

William

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_{Tuesday, October 2, 2018 1:52 PM}

Thanks for the reply William, I used that too before, and used it again now, but could not pinpoint any specific process other then multiple sessions of NTOSKRNL (please see picture below)

as of now it is 9:50 AM and it is over 80% CPU, by the afternoon, it will go 100% untill 4:30-5PM

_{Tuesday, October 2, 2018 3:13 PM}

I found this link, but the resolution looks a bit questionable.

https://superuser.com/questions/1051967/high-cpu-usage-by-service-host-local-system-win10-64-bit-ntoskrnl-exekesyn

Resolved the issue by what I think was turning off "Give me tips about Windows" in Devide Manage/System/Notifications. – A.S. Mar 12 '16 at 14:47

If you temporarily stop the Symantec services, does that change the behavior? Also try stopping other non-critical services to see if you can isolate the software that might be causing this.

_{Wednesday, October 3, 2018 1:26 AM}

Hi Camci M，

Thanks for your feedback. Based on my knowledge，Ntoskrnl.exe, short for Windows NT operating system kernel, is a fundamental part of the system. Usually, when you see the uncommon usage of high CPU or memory, you should shut down the possible programs that are causing the problem.

Please check if certain programs running during this time. Especially antivirus software running in the background. The antivirus software might have some conflicts with certain programs.

Besides，many users use windows search on the file server during that time？