With osxfs, latency is presently around 200μs for most operations or 20x slower. With a classical block-based file system, this latency is typically under 10μs (microseconds). For instance, the time between a thread issuing write in a container and resuming with the number of bytes written. Latency is the time it takes for a file system system call to complete.

With large sequential IO operations, osxfs can achieve throughput of around 250 MB/s which, while not native speed, will not be the bottleneck for most applications which perform acceptably on HDDs. In a traditional file system on a modern SSD, applications can generally expect throughput of a few GB/s.

At the highest level, there are two dimensions to file system performance: throughput (read/write IO) and latency (roundtrip time). Additionally, osxfs integrates a mapping between OS X's FSEvents API and Linux's inotify API which is implemented inside of the file system itself complicating matters further (cache behavior in particular). File system APIs are very wide (20-40 message types) with many intricate semantics involving on-disk state, in-memory cache state, and concurrent access by multiple processes. This means that, depending on your workload, you may experience exceptional, adequate, or poor performance with osxfs, the file system server in Docker for Mac. There is a lot of hate so better listen to the “members” instead of reading all the from the Docker for Mac team nailed the issue: Perhaps the most important thing to understand is that shared file system performance is multi-dimensional. This GitHub issue tracks the current state. But the bitter truth is it will take ages. Usually you would work on your source code and expect no slowdowns for building. When you develop a big dockerized application then you are in a bad spot. Let’s compare the results of Windows, Cent OS and Mac OS: Windows 10 100000+0 records in Write random data to a file in this directoryĭocker run -rm -it -v '$(PWD):/pwd' -w /pwd alpine time dd if=/dev/zero of=speedtest bs=1024 count=100000.We can spin up a container and write to a mounted volume by executing the following commands: The read and write access for mounted volumes is terrible.

They fixed many issues, but the bitter truth is they missed something important. Docker just released a native MacOS runtime environment to run containers on Macs with ease.

Docker on mac instruction