5.2 Identifying faulty parts

Key points

1. A PSU (power supply unit) feeds the system. The DGX H100 names them PSU0 to PSU5. A failed one shows an amber LED. nvsm show psus reports each PSU's health.

   What NVIDIA says (2)

   “Identify the broken power supply either by the amber color LED or by the power supply number”

   — DGX H100/H200 Service Manual: Power Supply Replacement

   “Look for any that do not report Status_Health=OK .”

   — DGX H100/H200 Service Manual: Power Supply Replacement

2. A baseline is a known-good result to compare against. NVIDIA expects the same test on different parts of the system to perform similarly. A repeatable gap on the same hardware points to a component in that hardware.

   What NVIDIA says (2)

   “When running the following tests, you should expect that performance between runs of the same configuration on distinct parts of the system should run in a similar time or at a similar performance level.”

   — DGX SuperPOD Administration Guide: System Health Checks and Debugging

   “However, over multiple runs on the same sets of hardware a difference is found, it can indicate an issue with some component of that system.”

   — DGX SuperPOD Administration Guide: System Health Checks and Debugging

Sample question

How can you identify a failed power supply on a DGX H100?