Chunk 4.0

## Summary This chunk focused on implementing an LXC container approach to bypass the VFIO/IOMMU P2P bottleneck that limited GPU communication in the KVM VM. The assistant guided the user through installing the NVIDIA driver (590.48.01) directly on the Proxmox host, converting the existing unprivileged LXC container 129 (`llm-two`) to privileged, and configuring bind-mounts for all 8 GPU device nodes. The critical achievement was confirming that inside the container, `nvidia-smi topo -m` shows the true bare-metal topology (`NODE` within sockets, `SYS` across sockets) instead of the `PHB` topology seen in the VM — meaning P2P DMA should theoretically work. The model cache was also copied from the VM's ZFS zvol to a shared dataset and bind-mounted into the container, avoiding a 296GB re-download. However, a major blocker emerged: CUDA runtime initialization (`cuInit`) fails with error code 3 (`CUDA_ERROR_NOT_INITIALIZED`) both on the host and inside the container, despite `nvidia-smi` detecting all 8 GPUs correctly. The open-source kernel module sees the Blackwell GPUs but CUDA cannot initialize, while the proprietary kernel module makes the GPUs completely invisible. The root cause appears to be a driver compatibility issue with the Proxmox VE kernel (6.8.12-9-pve) — the driver 590.48.01 lacks Blackwell GSP firmware files (only `gsp_ga10x.bin` and `gsp_tu10x.bin` exist), and the older PVE kernel may not support the Blackwell architecture's GSP requirements. This is a fundamental difference from the KVM VM, where the guest's own NVIDIA driver stack handled VFIO-passed GPUs without host-level GSP firmware dependencies. The session concluded with the assistant investigating kernel version and firmware limitations, with the LXC approach showing promise for P2P but blocked by host driver initialization issues that need resolution before the ML stack can function.

The LXC Experiment: From P2P Breakthrough to CUDA Dead End 2936 words

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