2V0-21.23 Question 361
Single answerAn administrator is troubleshooting a performance issue with virtual machines in a vSphere cluster. The administrator observes that VMs on a specific ESXi host are experiencing high memory contention and ballooning. Upon further investigation, it is found that this ESXi host has significantly less free memory compared to others in the cluster, despite having access to shared storage and vMotion being enabled. What could be the most likely reason for this issue?
- A
The vSphere Distributed Resource Scheduler (DRS) is in manual mode.
- B
The ESXi host has memory limits configured on its virtual machines.
- C
The shared storage is experiencing high latency, causing memory swapping.
- D
The vMotion network is misconfigured or experiencing high latency.
Show answer and explanation
Correct answer: A
Explanation
When DRS is in manual mode, it does not automatically distribute workloads across the cluster to balance resource utilization. This can result in specific hosts becoming overcommitted on memory while others remain underutilized. By setting DRS to automatic mode, the system can proactively migrate VMs to maintain resource balance and prevent issues like memory contention and ballooning.
- A. Correct.
If DRS is in manual mode, it will not automatically balance workloads across hosts, potentially resulting in memory contention on specific hosts. This is the most likely cause of the issue described.
- B. Incorrect.
While memory limits can cause virtual machine performance issues, they would not explain why one host has significantly less free memory compared to others in the cluster.
- C. Incorrect.
Shared storage latency can cause performance issues, but it is unrelated to memory contention or ballooning on a specific ESXi host in this context.
- D. Incorrect.
vMotion network issues could impact the migration of VMs, but there is no indication in the scenario of vMotion failures or attempts to migrate workloads.