mchusandClaude Opus 4.8
a9924b08b0
Replaces the old nvbandwidth-all-gpu-power-watch scenario (dropped: the power/IPMI-sampler framing was a dead-end — the blackbox shows every other load test, incl. NCCL all-reduce across all 6 GPUs, passes with power fully connected; only nvbandwidth on cross-socket GPU P2P reboots the box). nvbandwidth-acs-ab is a two-phase reproduction for the MSI CG480-S6053 case. Phase 1 disables PCIe ACS redirect at runtime via setpci (saving each bridge's original ACS control word to /run/bee-acs-orig) then runs nvbandwidth across all 6 GPUs — expected to survive. Phase 2 restores the saved ACS values and repeats — expected to reproduce the reboot. Safe phase first so its full blackbox reaches the USB stick before the risky phase can reset the box (sync-bracket before the final job flushes phase-1 evidence). ACS mutation runs via `bash -c` since scenario cmd is exec'd directly with no shell. Both shipped copies (repo scenarios/ and image overlay) identical; verified both parse via ParseScenarioJSON (4 jobs). Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>