Cases1 case

1 to 1 of 1

1. IL-0238 Xid 74 NVLink errors led the GPU faults and InfiniBand flash cuts failed tasks on DeepSeek's 10,000-GPU A100 cluster

   DeepSeek2024

   Symptoms

   On DeepSeek's Fire-Flyer 2 training cluster of 10,000 PCIe A100 GPUs, Xid 74 NVLink errors, which occur mainly on the NVLink Bridge between pairs of GPUs, were the most common GPU Xid error and occurred several orders of magnitude more often than other hardware faults. InfiniBand link flash cuts disrupted application communication and sometimes failed training tasks, and computational and GPU memory errors that ECC did not detect caused gradnorm spikes, loss explosions and even non-convergence of models.

   GPU unavailableLink flappingTraining job failureTraining divergence or loss spike

   Root cause

   Hardware failure

   Component

   GPU hardware and memoryInfiniBand fabric

   Contributing factor

   –

   Detection

   Xid errors were read from the NVIDIA driver's messages in the kernel or event log. A validator run weekly by the automatic operations system tested every node, and diagnosis tools such as hostping were integrated into the platform.

   Remediation

   • Reset the GPU to clear most GPU memory ECC errors, relying on A100 row remapping
   • Reset the GPU or rebooted the node after uncorrectable GPU errors
   • Ran a fieldiag test after Xid 119 and sent most such GPUs for RMA
   • Removed nodes that failed the weekly validator from the scheduling platform
   • Resumed interrupted training from checkpoints saved about every 5 minutes

   Lessons

   The best way to keep devices stable is to find problems before they happen, which is why the validator runs weekly. GPU ECC faults far outnumber CPU ones and need to be handled quickly so that performance and accuracy are not affected. Software-looking Xid errors such as illegal memory access may come from corrupted memory, so hardware faults should be considered once software bugs are ruled out. Whether to install NVLink should depend on actual need because of its drawbacks.

   View case

By root cause1