Comment by silentOpen | Hacker News Reader

Comment by silentOpen | Hacker News Reader

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Many developer use cases do not demand heavy bind mount file access. For example, incremental builds of static languages typically work fine.

docker/for-mac#77 is related to "bind mount" performance but docker/for-mac#668 is virtual block device performance. Have you posted a reproduction workload that demonstrates the performance problems you are having?

Docker 17.04 includes a `cached` bind mount flag that relaxes consistency of the mount in exchange for significantly reducing guest-host roundtrips especially for inefficient workloads that repeatedly access the same files.

We're seeing the same issue. We've been using shared folders with VMware for a long time, which are also slow (but not this slow).

There's a case for keeping the Docker environment stateless and expendable (wipe to restart), and keep certain things (PostgreSQL databases, for example) on the host machine. Currently, that's impossible because of the aforementioned issue.

I haven't tried the "cached" flag since it's still in beta, however.

Could you please link to some docs for the cached flag you mentioned? I can't find anything about it.

Documentation for 'cached' is on its way. There'll be a blog post up soon with a friendly introduction, and some representative benchmarks. In the meantime there's a drier but more detailed specification of the behaviour of 'cached' waiting in a pull request here:

  https://github.com/yallop/docker.github.io/blob/d9a57867/docker-for-mac/osxfs-caching.md

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