NCP-AIO Administration Practice Question
An administrator is preparing a multi-node NVIDIA DGX H100 cluster for a distributed training job using NVIDIA Base Command. The cluster nodes have InfiniBand adapters, but the job's inter-node throughput is far below expectations. The administrator runs `ibstat` and sees that the ports are in the INIT state rather than ACTIVE. Which action should the administrator take first?
⚠ Common exam trap
The trap here is assuming that low inter-node throughput is always a GPU or driver problem, when an InfiniBand port in INIT points to a fabric-layer subnet manager or link configuration issue.
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
✓
Verify that the InfiniBand subnet manager is running and that the IPoIB interfaces are configured correctly.
InfiniBand ports stuck in INIT have not been configured by a subnet manager, which is the authoritative service that initializes and activates fabric links. Checking the subnet manager and IPoIB configuration directly addresses why ports never reach ACTIVE. Without an active subnet manager, distributed training traffic cannot flow at expected speeds, so this is the correct first action.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Enable GPUDirect Storage on each node to bypass the CPU for inter-node communication.
Why it's wrong here
GPUDirect Storage accelerates local storage-to-GPU transfers via NVMe and does not govern InfiniBand port state. Enabling it will not change a port stuck in INIT, because INIT indicates the subnet manager has not configured the port or the link is not yet joined to the fabric. This action leaves the actual fabric-level problem unaddressed and wastes time on an unrelated data path feature.
- ✗
Reinstall the NVIDIA GPU driver on all nodes to reset the InfiniBand firmware.
Why it's wrong here
GPU driver reinstallation does not control InfiniBand port states. The INIT state is a fabric-layer condition managed by the subnet manager and link training, not by GPU software. Reinstalling drivers across a production cluster would cause unnecessary downtime and would not move ports to ACTIVE, so it is both disruptive and ineffective for this symptom.
- ✗
Disable ECC memory on the GPUs to increase available bandwidth for inter-node traffic.
Why it's wrong here
ECC memory protects GPU memory integrity and has no bearing on InfiniBand fabric initialization. Turning it off would reduce data reliability without changing the port state or improving inter-node throughput. The INIT state points to a fabric configuration issue, so altering GPU memory settings misdiagnoses the problem and introduces a data-integrity risk.
- ✓
Verify that the InfiniBand subnet manager is running and that the IPoIB interfaces are configured correctly.
Why this is correct
An InfiniBand port remains in INIT when it has not been initialized by a subnet manager, so checking that the subnet manager service is active on the fabric and that IPoIB (or RDMA) interfaces are up is the correct first diagnostic step. Without subnet manager configuration, ports never transition to ACTIVE and inter-node bandwidth collapses regardless of GPU or driver health.
Visual reference
About these practice questions
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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 NVIDIA exam blueprint
This NCP-AIO practice question is part of Courseiva's free NVIDIA 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 NCP-AIO exam.