cp crawls. npm install takes forever. The exact same command, run one directory over, is instant. If you've used WSL2 long enough, you may have hit this. This post covers what's actually causing it, and how to find the specific culprit in your own setup — once you know that, the fix is usually obvious. TL;DR: WSL2 itself isn't slow. Crossing the boundary between the Linux filesystem and the Windows filesystem ( /mnt/c ) carries a real, measurable cost, and that cost lands hardest on wo...