An administrator is troubleshooting a CPU issue for a virtual machine. The following is seen in esxtop:
CPU0 is at 100% usage
The remaining logical CPUs are close to 0%
%RDY value is consistently above 10%
What is likely the cause of the CPU issue?
A.
The virtual machine has a CPU limit configured.
B.
The virtual machine’s guest operating system is configured for SMP.
C.
The virtual machine has CPU affinity configured.
D.
The virtual machine is configured with a CPU reservation.
Explanation:
Explanation/Reference:
C is correct.
http://pubs.vmware.com/vsphere-60/index.jsp#com.vmware.vsphere.resmgmt.doc/GUID-5FCC0AAA-9D58-4EDF-9A5F-8628F1C8B830.html
Working link:
https://docs.vmware.com/en/VMware-vSphere/6.0/com.vmware.vsphere.resmgmt.doc/GUID-5FCC0AAA-9D58-4EDF-9A5F-8628F1C8B830.html
C does not convince me.
The question states that the other vCPUs are close to 0 which would imply that other processes associated with the VM (keyboard, display) would still have free CPU resources on the remaining idling vCPUs.
I would guess that the virtual machine is configured for SMP (multiple vCPUs) but can only make use of 1x vCPU (single threaded app) and has a low CPU limit configured, which would explain the high vCPU usage and RDY time inside the VM.
So:
A
Even though the other CPUs are present while not being used AND if affinity is configured, the VM may not be allowed to use the other CPUs on the host (if they’re even present or not busy with other things). C at least for this moment, makes sense to me.
TEST