September 20, 2020

Microsoft is working hard to improve the I/O performance of the Windows Subsystem for Linux

2 min read

The Windows Subsystem for Linux, also known as WSL is an exciting product of Microsoft’s implementation of running Linux binaries on Windows 10 and more recently Windows Server. Phoronix said that in their benchmarks, WSL usually has high performance, but the areas it faces are I/O and storage performance.

WSL has been working hard to improve its I/O performance because it must handle the operation of Linux files and keep track of all relevant metadata while backing up through the Windows NTFS file system. This overhead has a significant impact on slowing down programs/services/benchmarks that require frequent reads/writes, and in CPU/system workloads, WSL is very similar to bare-metal Windows 10 performance or the performance of various Linux distributions.

Microsoft said they have developers dedicated to improving WSL I/O performance. Microsoft’s Rich Turner reiterated this on GitHub’s issue tracker

  1. Disk IO perf remains VERY HIGH up our list of improvements we’re actively working on. Once we have an actionable solution to this issue, you’ll barely be able to NOT hear about it, especially if you follow Tara or me on Twitter, and keep an eye on the Command-Line Blog where we’ll definitely announce any such improvements.
  2. We’ll also do our best to update issues/threads like this one when we do have something positive to report, but with the number of threads x number of repos/forums/etc., we may not reach all of you, so would appreciate everyone’s help when we DO announce new features or improvements

Microsoft has not yet explained when these improvements to I/O may come, but we hope it will be available in time for the next Windows 10 update. The Windows 10 Redstone 5 update is expected to be released in October, and we hope that we will learn more about WSL improvements before the next milestone.