CV0-003 · Question #116
A host with 30 VMs has 64GB of RAM, four quad-core CPUs, four 1-gigabit NICs and is connected to a NAS that provides NFS volumes. The hosted VMs are reporting slow performance. From the information…
The correct answer is D. Insufficient network capacity. With 30 VMs sharing only four 1-gigabit NICs and relying on NFS storage over the same network, the network is the most likely bottleneck causing slow VM performance.
Question
A host with 30 VMs has 64GB of RAM, four quad-core CPUs, four 1-gigabit NICs and is connected to a NAS that provides NFS volumes. The hosted VMs are reporting slow performance. From the information given, which of the following is the MOST likely cause of the slow performance?
Options
- AInsufficient NAS capacity
- BThe server is using 110V instead of 220V
- COne hard drive has failed in the RAID 5
- DInsufficient network capacity
How the community answered
(38 responses)- A11% (4)
- B5% (2)
- C18% (7)
- D66% (25)
Why each option
With 30 VMs sharing only four 1-gigabit NICs and relying on NFS storage over the same network, the network is the most likely bottleneck causing slow VM performance.
NAS capacity refers to available storage space, not throughput; running out of space causes write failures, not general slowness.
Enterprise servers auto-detect input voltage and function correctly on either 110V or 220V, so power input does not affect VM performance.
A single failed drive in RAID 5 causes degraded-mode performance, but no failed drive is mentioned in the scenario and this would typically trigger alerts rather than subtle slowness.
Four 1-gigabit NICs must carry both VM network traffic and NFS storage I/O for 30 VMs simultaneously, making network saturation the most probable bottleneck. NFS is especially sensitive to network bandwidth and latency, so heavy shared use across 30 VMs over 4 GbE links would directly cause the observed performance degradation. No other constraint described - RAM, CPU, or storage capacity - is indicated as a problem by the given specs.
Concept tested: Network bandwidth bottleneck in virtualized NFS environments
Source: https://docs.vmware.com/en/VMware-vSphere/8.0/vsphere-networking/GUID-8E7B5DBF-72BA-4B93-9A96-1AC9BDDAB73C.html
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