vSphere Performance and Scaling →mediumMultiple ChoiceObjective-mapped

VCP-DCV vSphere Performance and Scaling Practice Question

Exhibit

Refer to the exhibit.
```
GID   NAME      NWLD   %USED   %RUN   %SYS   %WAIT   %RDY   %CSTP   %MLMTD
12345 VM_01       4     20.0    15.0    5.0   25.0    45.2   30.1     0.0
```

Refer to the exhibit. An administrator runs esxtop and sees the above output for a virtual machine. What is the most likely cause of the performance issue?

⚠ Common exam trap

Many candidates confuse high %RDY with memory overcommitment or general host contention, but the specific clue is the vCPU count exceeding physical cores, which directly points to CPU overcommitment as the root cause.

Answer choices

Why each option matters

Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.

Correct answer & explanation

✓

The VM has too many vCPUs for the available physical cores.

The exhibit shows a virtual machine with 8 vCPUs but only 4 physical cores (PCPU) available, as indicated by the %USED and %RUN columns. This leads to CPU ready time (%RDY) being high, which is a classic symptom of CPU overcommitment where the VM's vCPU count exceeds the available physical cores, causing scheduling contention. Option D is correct because the VM has too many vCPUs for the available physical cores, resulting in excessive ready time and degraded performance.

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

✗
The VM is running on a host with Hyper-Threading disabled.
Why it's wrong here
Disabling HT would reduce available logical CPUs but would not directly cause high %CSTP; it would more likely increase %RDY.
✗
The memory of the VM is overcommitted.
Why it's wrong here
Memory overcommitment would show as high %SWP% or memory ballooning, not high %RDY and %CSTP.
✗
The host has too many other VMs competing for resources.
Why it's wrong here
While competition can increase %RDY, it does not specifically cause high %CSTP unless the VMs themselves have many vCPUs.
✓
The VM has too many vCPUs for the available physical cores.
Why this is correct
High %RDY indicates vCPU contention, and high %CSTP indicates co-scheduling overhead, both symptoms of vCPU overcommitment.
✗
The VM has CPU affinity configured to a single core.
Why it's wrong here
CPU affinity would force the VM to run on a specific core, potentially increasing %RDY if that core is busy, but %CSTP would not be elevated because there is no co-scheduling across multiple physical CPUs.

Go deeper

VCP-DCV vSphere Performance and Scaling Practice Question

Exhibit

Why each option matters

Option-by-option breakdown

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