Link to home
Start Free TrialLog in
Avatar of Los Angeles1
Los Angeles1

asked on

VMWare, 2 VM's and a hypervisor

I have a 16 core machine

I have 2 VM's, with each core assigned eight cores.  So no cores are available for a hypervisor

So which does the hypervisor reside since it does not have any cores assigned to it

... or more specifically, which of the 2 VM's will the hypervisor drain resources from, and how can I tell which VM it is currently draining resources from

Thanks
Avatar of coolsport00
coolsport00
Flag of United States of America image

First of all, depending on the VM & that app that is running inside of it, you shouldn't allocate more than 1 or typically at most TWO vCPUs to a VM. A VM utilizes resources of the Host it resides on. There really isn't a way to tell what specific Host CPU and/or Core the VM utilizes as that is controlled by the VKernel CPU Scheduler.

Regards,
~coolsport00
Hi,

First you need to monitor your environment to check who consumes what (cpu, memory etc)

You can use a free tool to gather that data, In my case i use Veeam One Free edition (you can get it here to collect and troubleshoot my environment. Maybe you can remove some cores from the VMs to your hypervisor since is to much for a VM also not the best practices to go for.

Also you can check the users articles like the one hanccocka wrote  HOW TO:  Performance Monitor vSphere 4.x or 5.0.
ASKER CERTIFIED SOLUTION
Avatar of coolsport00
coolsport00
Flag of United States of America image

Link to home
membership
This solution is only available to members.
To access this solution, you must be a member of Experts Exchange.
Start Free Trial
Avatar of asavener
I have 2 VM's, with each core assigned eight cores.  So no cores are available for a hypervisor
This statement is incorrect.

The hypervisor schedules time on the CPUs, and it will always schedule time for itself.

Since all vCPUs have to be scheduled at the same time, you are likely running into a scheduling bottleneck.  When the hypervisor is using CPU, only one of your VMs can be scheduled for CPU as well.  Bascially, you will always have seven idle cores.

Reduce the number of vCPUs on your VMs.  Unless you're in a lab setting where you're testing high performance computing, it's unlikely that you really need eight vCPUs.  If you do need eight vCPUs, then you need at least two hosts.