Troubleshooting — Kernel Module Installation

Because Phoenix uses ZONE_DEVICE to provide memory-mapping services, no other application or kernel driver may be using the GPU’s PCIe BAR resources when phxfs.ko is inserted.

If you see:

insmod: ERROR: could not insert module phoenixfs.ko: Operation not permitted

the BAR resources are likely already in use. Resolve as follows.

1. Check for user-space processes using the GPU

sudo lsof /dev/nvidia*

Terminate any listed processes, then retry insmod.

2. Check for kernel drivers using the GPU

sudo lsmod | grep nvidia

Typically nvidia_drm is held by other DRM modules, partially occupying GPU memory. Either:

• Add nvidia_drm to the system blacklist to prevent auto-loading, or

• Manually rmmod nvidia_drm and its dependents, then retry.