VCP-DCV vSphere Performance and Scaling Practice Question
This VCP-DCV practice question tests your understanding of vsphere performance and scaling. The scenario asks you to isolate a root cause — eliminate options that address a different problem before choosing. After answering, compare your reasoning against the explanation and wrong-answer breakdown below. Once you have made your selection, read the full explanation to reinforce the concept and understand why each distractor is designed to mislead on exam day.
A vSphere administrator is troubleshooting a VM that hosts a critical database. The VM is configured with 8 vCPUs and 64 GB memory on an ESXi host with two 10-core CPUs (hyperthreading enabled). Performance charts show CPU ready time averaging 12% during peak hours, and the database application is experiencing high transaction latency. The administrator has verified that no other VMs are contending for CPU. Which action will most likely reduce CPU ready time without negatively impacting database performance?
Clue words in this question
Noticing these words before you look at the options changes how you read each choice.
Clue: "most likely"
Why it matters: Probability qualifier — the question wants the most probable cause or outcome, not a guaranteed one. Eliminate low-probability options.
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Reduce the number of vCPUs assigned to the VM to 4.
Option C is correct because reducing the number of vCPUs to match the actual workload reduces scheduler overhead and improves cache locality. A VM with 8 vCPUs on a host with 40 logical CPUs should not normally have high ready time unless the vCPU count is excessive relative to the workload. Reducing to 4 vCPUs often resolves contention without degrading throughput because many database workloads do not scale linearly beyond 4 vCPUs. Option A is wrong because disabling hyperthreading reduces logical CPUs, potentially increasing contention. Option B is wrong because increasing memory does not affect CPU ready time. Option D is wrong because CPU affinity can lead to unbalanced load and is not a best practice for DRS clusters.
Key principle: Count usable hosts — not total addresses — and remember that the network and broadcast addresses are not available to hosts in standard IPv4 subnets.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
✗
Disable hyperthreading on the host.
Why it's wrong here
Disabling hyperthreading reduces logical CPUs, which could increase CPU ready time.
✗
Assign a CPU affinity mask to pin the VM to specific physical cores.
Why it's wrong here
CPU affinity can cause imbalances and is not recommended for DRS-managed clusters.
✗
Increase the VM's memory reservation.
Why it's wrong here
Memory reservation does not affect CPU scheduling.
✓
Reduce the number of vCPUs assigned to the VM to 4.
Why this is correct
Reducing vCPUs decreases CPU scheduling overhead and can lower ready time for many applications.
Clue confirmation
The clue word "most likely" in the question point toward this answer.
Common exam trap: usable hosts are not the same as total addresses
Subnetting questions often tempt you into counting all addresses. In normal IPv4 subnets, the network and broadcast addresses are not usable host addresses.
Detailed technical explanation
How to think about this question
Subnetting questions test whether you can identify the network, broadcast address, usable range, mask and correct subnet. Slow down enough to calculate the block size correctly.
KKey Concepts to Remember
CIDR notation defines the prefix length.
Block size helps identify subnet boundaries.
Network and broadcast addresses are not usable hosts in normal IPv4 subnets.
The required host count determines the smallest suitable subnet.
TExam Day Tips
→Write the block size before choosing the subnet.
→Check whether the question asks for hosts, subnets or a specific address range.
→Do not confuse /24, /25, /26 and /27 host counts.
Key takeaway
Count usable hosts — not total addresses — and remember that the network and broadcast addresses are not available to hosts in standard IPv4 subnets.
Real-world example
How this comes up in practice
A network engineer segments a warehouse floor into three subnets: 20 scanners, 5 printers, and 2 management hosts. Picking the wrong mask wastes addresses or leaves too few usable hosts. Exam questions test whether you can apply CIDR notation, calculate block size, and identify the correct usable-host range for a given prefix.
What to study next
Got this wrong? Here's your next step.
Review block sizes, usable host formulas (2^n − 2), and how to find network and broadcast addresses for /24 through /30. Then practise related VCP-DCV subnetting questions on CIDR, address ranges, and subnet selection.
vSphere Performance and Scaling — This question tests vSphere Performance and Scaling — CIDR notation defines the prefix length..
What is the correct answer to this question?
The correct answer is: Reduce the number of vCPUs assigned to the VM to 4. — Option C is correct because reducing the number of vCPUs to match the actual workload reduces scheduler overhead and improves cache locality. A VM with 8 vCPUs on a host with 40 logical CPUs should not normally have high ready time unless the vCPU count is excessive relative to the workload. Reducing to 4 vCPUs often resolves contention without degrading throughput because many database workloads do not scale linearly beyond 4 vCPUs. Option A is wrong because disabling hyperthreading reduces logical CPUs, potentially increasing contention. Option B is wrong because increasing memory does not affect CPU ready time. Option D is wrong because CPU affinity can lead to unbalanced load and is not a best practice for DRS clusters.
What should I do if I get this VCP-DCV question wrong?
Review block sizes, usable host formulas (2^n − 2), and how to find network and broadcast addresses for /24 through /30. Then practise related VCP-DCV subnetting questions on CIDR, address ranges, and subnet selection.
Are there clue words in this question I should notice?
Yes — watch for: "most likely". Probability qualifier — the question wants the most probable cause or outcome, not a guaranteed one. Eliminate low-probability options.
What is the key concept behind this question?
CIDR notation defines the prefix length.
About these practice questions
Courseiva creates original exam-style practice questions with explanations and wrong-answer analysis. It does not publish real exam questions, exam dumps, or protected exam content. Learn why practice questions differ from exam dumps →
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
This VCP-DCV practice question is part of Courseiva's free VMware certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the VCP-DCV exam.
Question Discussion
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
Sign in to join the discussion.