WSL From DrvFs in WSL 1 to Plan 9 to virtiofs, cross-OS file access in WSL 2 has improved with each generation. A new change gives each virtio device its own dedicated DMA pool, removing the last major contention point on the virtiofs path.

If your workflow crosses the Windows/Linux boundary, file I/O performance in WSL 2 has been getting steadily better. A change landed in WSL 2 in May 2026 that removes one of the last remaining bottlenecks on the virtiofs path. To understand why it matters, it helps to follow how cross-OS file access has evolved.

How we got here

WSL 1 (2016) handled Windows drive access through DrvFs, a custom filesystem driver running inside the Windows NT kernel. Because WSL 1 ran Linux processes directly on the Windows kernel through a compatibility layer , file operations on /mnt/c could reach NTFS almost directly. Performance was good for file-heavy workloads.

WSL 2 (May 2019) replaced that model with a full Linux kernel in a lightweight Hyper-V VM .…