This may break your docker environments. Use at your own risk

Docker.img: Use raw disk image at Docker for Mac

Current Docker for Mac(as long as 17.03.0-ce-mac1) use qcow2 as disk image format. But qcow2 is worse performance than raw format.

This short script change image type qcow2 to raw.

Usage

Install

curl https://raw.githubusercontent.com/mzp/Docker.img/master/install.sh | bash

Uninstall

cd /Applications/Docker.app/Contents/MacOS
rm com.docker.hyperkit
mv com.docker.hyperkit.original com.docker.hyprekit

cd ~/.docker
rm -rf jp.mzp.img

Benchmark

Run fio on MacBookPro(Late 2016).

fio -filename=/tmp/test2g -direct=1 -rw=read -bs=4k -size=2G -numjobs=64 -runtime=10 -group_reporting -name=file1
fio -filename=/tmp/test2g -direct=1 -rw=write -bs=4k -size=2G -numjobs=64 -runtime=10 -group_reporting -name=file1

Sequential Read

	Average(MiB/s)	Min(MiB/s)	Max(MiB/s)
native	361	361	361
qcow2	46	46	46
docker machine	105	105	105
raw	147	147	147

Sequential Write

	Average(MiB/s)	Min(MiB/s)	Max(MiB/s)
native	487	487	487
qcow2	29	29	29
docker machine	51	51	51
raw	45	45	45