Mellanox OFED Driver Mismatch
New InfiniBand adapters (like ConnectX-7) require specific OFED versions. Mismatches with the host kernel or existing driver stack break the network fabric, making nodes unreachable or failing RDMA.
New InfiniBand adapters (like ConnectX-7) require specific OFED versions.
What this failure is
Mellanox OFED Driver Mismatch is a Hardware/Vendor failure seen during ML training runs. New InfiniBand adapters (like ConnectX-7) require specific OFED versions. Mismatches with the host kernel or existing driver stack break the network fabric, making nodes unreachable or failing RDMA. Common tags: Mellanox, Ofed, Infiniband, Rdma.
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Why it happens (the mechanism)
The installed Linux kernel was updated, breaking the DKMS compilation for the current MLNX_OFED driver. A mismatch between the host OFED driver and the containerized OFED libraries. Taken together, these mechanisms explain why the failure is reproducible, why it tends to surface on specific workloads or scales, and why generic mitigation attempts often fall short without addressing the underlying cause.
What you'll observe
- Nodes become unreachable via SSH after applying updates
- NCCL falls back to Ethernet/TCP instead of InfiniBand
- IB verbs fail to initialize during training startup
Common symptoms and what they mean
| Symptom | Why it happens |
|---|---|
| ibv_devinfo shows 'Fatal' or no devices found | The installed Linux kernel was updated, breaking the DKMS compilation for the current MLNX_OFED driver |
| dmesg shows MLNX_OFED module load failures or unresolved symbols | A mismatch between the host OFED driver and the containerized OFED libraries |
| NCCL warns: 'NET/IB : No device found' | The installed Linux kernel was updated, breaking the DKMS compilation for the current MLNX_OFED driver |
Which systems are affected
- Clusters utilizing Mellanox/NVIDIA InfiniBand (ConnectX-6, ConnectX-7)
- Environments with automated kernel patching without pinned OFED versions
How to confirm this is the problem
Use this checklist to test the hypothesis against a small reproduction. No single line proves the root cause, so preserve the preceding events and compare one variable at a time.
- ✓Reproduce the failure from a clean checkpoint/seed: the symptom must appear without warm-up state from a previous run.
- ✓Verified signal present: ibv_devinfo shows 'Fatal' or no devices found
- ✓Verified signal present: dmesg shows MLNX_OFED module load failures or unresolved symbols
- ✓Verified signal present: NCCL warns: 'NET/IB : No device found'
- ✓A targeted fix from the "How to fix it" section eliminates or substantially reduces the symptom within one validation pass.
The fix and the prevention pattern
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Root cause
- The installed Linux kernel was updated, breaking the DKMS compilation for the current MLNX_OFED driver
- A mismatch between the host OFED driver and the containerized OFED libraries
The fix and how to prevent it
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