If you are a developer who uses Docker Desktop on your Mac, you might have noticed that it can be quite slow when it comes to file sharing between the host and the guest operating systems. This can affect the performance and responsiveness of your applications, especially if they rely on a lot of disk IO operations. Fortunately, there is a new feature that can significantly improve the file sharing speed and make your development experience much smoother: VirtIOfs.

VirtIOfs is a virtualization technology that allows faster and more efficient file sharing between the host and the guest operating systems. It uses a shared memory region to transfer data between the two systems, instead of copying files back and forth. This reduces the CPU usage and memory consumption, as well as the latency and overhead of file sharing. According to a recent benchmark by Docker, VirtIOfs can make Docker Desktop on MacOS up to 98% faster than without VirtIOfs.

Some of the benefits of using VirtIOfs for file sharing are:

  • Reduced CPU usage and memory consumption: VirtIOfs eliminates the need for copying files between the host and the guest operating systems, which saves CPU cycles and memory space. This can also free up resources for other tasks and improve the overall performance of your system.
  • Improved performance and responsiveness of applications: VirtIOfs enables faster file access and modification, which can improve the speed and responsiveness of your applications. For example, if you are using a web framework that reloads your code on every change, you will notice a much shorter feedback loop with VirtIOfs enabled.
  • Enhanced compatibility and security: VirtIOfs supports all file system features that are supported by MacOS, such as extended attributes, hard links, symlinks, etc. This means that you don't have to worry about any compatibility issues or data loss when using VirtIOfs. Moreover, VirtIOfs uses a secure communication channel between the host and the guest operating systems, which prevents any unauthorized access or tampering with your files.

To enable VirtIOfs on Docker Desktop, you need to follow these simple steps:

  • Update to the latest version of Docker Desktop and MacOS: You need to have Docker Desktop version 4.6.0 or higher and MacOS version 12.0 or higher to use VirtIOfs. You can check your current versions by going to About Docker Desktop and About This Mac in your menu bar.
  • Go to Preferences > Experimental Features and check the box for Use virtiofs for file sharing: This will enable VirtIOfs as the default file sharing mechanism for Docker Desktop on MacOS. You can also toggle this option on or off for individual containers by using the --mount flag with the type=virtiofs option.
  • Restart Docker Desktop and enjoy the speed boost: After enabling VirtIOfs, you need to restart Docker Desktop for the changes to take effect. You should notice a significant improvement in the file sharing speed and performance of your applications.

Here are the official release announcement: Speed boost achievement unlocked on Docker Desktop 4.6 for Mac | Docker

VirtIOfs is a game-changer for developers who use Docker Desktop on their Macs. It can make your development experience faster, smoother, and more enjoyable. If you haven't tried it yet, I highly recommend you to give it a shot and see for yourself how much difference it can make.