CPU high usage

[aa2017]

We have a Windows Server 2003 file server running on an ESXI 6.5 Vsphere host. We notice at some point (not always) when the user is running the batch job this particular file server spikes its CPU and in turn the batch jobs do not run or runs slowly. I have been looking into ESXTOP and troubleshooting it but would like to learn more from the experts. 

Appreciate it.

Thanks

[kastlr]

Hi,

batch jobs are usually performing single threaded tasks, so even if your Windows VM would have multiple vCPUs I'm pretty sure only one of them is working on the job.

But please allow some questions

• Why are you still running such an old guest OS?
• What does PerfMon report when the batch job is running?
• What kind of activity does the batch job perform, because High CPU Usage might also be seen when i.e. Network or Storage isn't fast enough and CPUs had to wait on completion of those tasks?
• What kind of problems does the high CPU spikes causes, or is this more a cosmetic issue?

[aa2017]

Hi Kastlr

Thanks for the response. I will give you some more insights. Your information was great and really helpful,

• Why are you still running such an old guest OS? - Well its time to get it to new system but due to so many work, it is not not become the priority.
• What does PerfMon report when the batch job is running? - We have not tested it, the batch job is run through Citrix.
• What kind of activity does the batch job perform, because High CPU Usage might also be seen when i.e. Network or Storage isn't fast enough and CPUs had to wait on completion of those tasks? - We do not know what the batch job does, and I have asked the same question, what the batch job does and how that would trigger something on the file server. What it is doing on the file server.
• What kind of problems does the high CPU spikes causes, or is this more a cosmetic issue? It basically slows down the batch job or does not run it. 

i hope that answers the question. Also, I saw something today as I was  investigating through ESXTOP as well as through perfomance monitor. That the High CPU Ready time was noticed.  So, what would you think about this?

[kastlr]

Hi,

so if you don't know what the batch job does, why don't you prevent it from running?

First you need to figure out if this job is needed or not.

When the job is running, did you check Task Manager to figure out the name of the process consuming the CPU resources.

That would allow you to search the web to figure out 

• to which application the process belongs
• if it's a critical, optional or cosmetic task for the application
• if the application vendor offers some configuration guidance how to lower the CPU resource requirements
• maybe a newer version of the process might be more effective 

To be honest, this topic isn't a VMware related topic.

Instead you should reach out to the application or batch vendor and address your concerns there.