Use of hypervisor.cpuid.v0??

[Venkat_A]

Can someone tell me what is the use of vmware hypervisor.cpuid.v0???

what will happen if I make it false / true?

Will it impact any performance on my VM's?

Regards

Venkat

[jrmunday]

This basically reports up that the system is runing on a virtual machine, so a use case would be for testing a nested installation of Hyper-V on a VM. Hyper-V checks to see if it's running in a VM and won't work if it is, so this gets you past that check.

[Venkat_A]

I just want to know, if i used it in Prod Machiens, what is Pros and Cons of that?

[jrmunday]

What are you trying to achieve? I wouldn't be changing settings without an actual requirement - I assume you have one?

[Venkat_A]

Then let me explain you the scenario what we are facing..

I have a VM, in that Java application is running. that application uses 2 JVM's, when I try the applciation performance on  my laptop it is taking 8 seconds,

but when i do the same thing on a VM, it is taking 20+ seconds.

we followed best practices for the java to run on the machine.

for a JVM we kept 4048 as HEAP memory and for 2 JVM's it is taking 8GB and excel is running and it is 2 GB and OS 2GB, total is 12GB assigned memory.

Now even after assign that much, it is showing the slow performance,

now after making hypervisor.cpuid.v0= False, it slightly increased the performance, I am wondering why it affecting this parameter? what if I make hypervisor.cpuid.v0=True, and check, I want to know the PROS and CONS of using this parameter?

Storage is FC .

Thanks

[jrmunday]

One thing that comes to mind is host BIOS settings ... power settings should be set to MAX Performance and power state C1E should be disabled.

What model and spec are your ESXi hosts? Are you running the latest firmrware and drivers?

[Venkat_A]

it is Dell poweredge R910 intel xeon 2.27GHZ

vmaware esx 5.0.0, build 768111

[jrmunday]

Did you check the BIOS for power management and C states?

[Venkat_A]

how to verify those things?

[jrmunday]

You need to access the host console, reboot, enter the BIOS and check these setting;

Processor Settings;

Power Management Settings;

[admin]

Windows will use different strategies for QueryPerformanceCounter depending on whether it thinks it's running on bare metal, in a Hyper-V VM, or in a non-Hyper-V VM.  The slow path used for non-Hyper-V VMs can negatively impact performance.