WSL 2 is getting faster Windows file system access

Original Article ↗ Hacker News Discussion ↗

Benchmarks and Technical Notes

  • One user shared a Hugo build on Ryzen 7 + SSD: ~50s on WSL’s internal ext4 VHD vs ~75s on Windows files via virtiofs, with ~10s extra from Defender. They still saw this as a big improvement over the previous 9P-based DrvFs and a “good” result for cross-OS access.
  • Clarification: “drvfs” is the mount type; it can use 9P (old, slow) or virtiofs (new). The benchmark compared WSL’s internal filesystem vs virtiofs access to Windows files, not 9P.
  • Some report noticeably faster WSL startup after upgrading.

Why Filesystem Performance Matters

  • Strong consensus that WSL2 access to /mnt/c (Windows drives) is/was painfully slow, especially for many small files (e.g., node_modules, Ruby requires, Next.js dev server, git operations).
  • Several note that deleting large node_modules trees from WSL on Windows can take minutes vs seconds in native Windows.
  • Explanations vary: some blame NTFS itself; others say NTFS is fine and the real cost is Windows filesystem filter drivers (Defender, AV, backup, cloud sync).

Virtiofs vs 9P and Limitations

  • 9P-over-virtio was used because it already existed in Linux virtualization and is simple, but is “NFS-like” slow.
  • virtiofs is expected to close part of the gap, but only affects access from WSL to Windows files. Work done inside WSL’s own ext4 VHD remains fastest.
  • Some emphasize that even with virtiofs, you still hit Windows-side overhead (filters, Defender).

Developer Workflows and Workarounds

  • Common advice: keep dev projects in WSL’s ext4 filesystem; copy to/from /mnt/c as needed.
  • Others mount separate ext4 volumes in WSL and access them from Windows, which can be faster than the reverse.
  • Some use WSL1 for light tasks (e.g., SSH) because it has no VM overhead, but WSL2 is needed for Docker/containers.

OS Choice, Gaming, and LLMs

  • Several report abandoning Windows for macOS or Linux primarily due to WSL/Windows filesystem slowness, along with annoyance at Microsoft’s cloud/ads integration.
  • Counterpoints: Windows + WSL is viewed by others as a very good dev environment, especially when combined with gaming needs and widespread Windows-only tools (Adobe, Office/VBA, VPNs, FPGA and game dev tooling).
  • Debate over gaming: some say Windows is clearly ahead (drivers, anti-cheat), others claim modern Linux + Proton often matches or beats Windows perf, with anti-cheat the main blocker.
  • Multiple comments say LLMs (Claude, ChatGPT) have dramatically reduced the friction of moving to Linux, helping with distro choice, configuration, and scripting.

Enterprise and Strategic Context

  • Many use WSL because corporate policy forbids bare-metal Linux but allows Windows.
  • Some see WSL as “the only sane way” to get near-Linux in such environments.
  • A few argue Microsoft should have fixed Windows filesystem performance and NT side instead of pivoting from WSL1’s syscall translation to WSL2’s VM; others think the VM approach was necessary to support Docker and full Linux semantics.