VCP-DCV vSphere Performance and Scaling Practice Question
An ESXi host experiences high memory ballooning in virtual machines. The administrator checks the host's memory metrics and sees a high swap rate. The host has 512 GB of memory, and the VMs are configured with memory reservations. Which configuration is most likely contributing to the excessive swapping?
⚠ Common exam trap
VCP-DCV often tests the interaction between reservations and overcommitment — the trap is blaming shares or TPS when the real driver is reserved memory reducing the reclaimable pool.
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
✓
Memory overcommitment is high, and some VMs have large memory reservations.
High memory overcommitment combined with large VM memory reservations forces ESXi to reclaim memory from unreserved VMs via ballooning and, when that is insufficient, host-level swapping. Reservations lock physical memory for some VMs, leaving less for others, which amplifies ballooning and swap activity on the overcommitted host. The correct fix is to reduce overcommitment or right-size reservations.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Memory shares are set too low for the VMs experiencing ballooning.
Why it's wrong here
Shares only arbitrate contention once the host is already overcommitted; they do not create the memory shortfall that forces swapping. Low shares would be the correct lever when a specific VM must yield memory to higher-priority workloads during contention.
- ✓
Memory overcommitment is high, and some VMs have large memory reservations.
Why this is correct
Large reservations lock physical pages, preventing the balloon driver from reclaiming them, so the host must swap to satisfy remaining demand. With 512 GB and overcommitment, reserved memory cannot be compressed or ballooned, forcing the VMkernel swap path and producing the high swap rate observed.
- ✗
The host is configured for NUMA interleaving, causing memory access delays.
Why it's wrong here
NUMA interleaving spreads memory across nodes to balance bandwidth, adding latency but not consuming host memory, so it cannot drive swap. Interleaving is correct when a single wide VM needs uniform bandwidth across all NUMA nodes.
- ✗
Transparent Page Sharing (TPS) is enabled and is aggressively sharing memory pages.
Why it's wrong here
TPS reclaims identical pages across VMs, which reduces memory pressure rather than causing swap; with reservations in place, the real trigger is host overcommitment exceeding available physical memory. TPS is the right choice when many clones share identical pages and the goal is consolidation.
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JA
Written and reviewed by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
Last reviewed September 2026 · checked against the official VMware exam blueprint
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.