Slow disk performance in Docker container

so you are using a mac. That means you are installing docker on virtualbox.. so here's how storage goes

os x -> virtualbox vm -> linux FS of choice -> aufs -> docker

So you are adding another VM layer on top of what docker already has on it.

I don't think anyone has claimed docker IO will perform close to what you see on the host.

The issue is vboxsf, not docker. Spent days playing with this. vboxsf is incredibly incredibly slow. NFS is faster, depends what you're wanting to do though.

I decided I don't need the files on my host anyway, so subsequently just created a new virtual disk in my vagrant file which is where my source gets cloned to, and then I just back that file up.

This is hard to do with boot2docker I found, so I just use virtual box and vagrant with an image I made, hp-ess/docker which has the latest docker and docker compose in.