Slow Volume mounts performance

[matejsp]

I am in a process of validating colima for development (instead of Docker Desktop).

Using volume mounts for python environment using volume pointing to our source code.
If I compare Docker Desktop mounted volume performance and colima it is a lot slower (2x slower).

docker-compose:

    volumes:
      - ./:/dev:cached

Running time pytest in our code (with 70k of files):

case 1: Docker for Desktop
real 0m10.292s
user 0m4.504s
sys 0m0.768s

case 2: colima (same as before)
real 0m21.650s
user 0m6.904s
sys 0m0.750s

case 3: colima copy all files to not mounted folder inside container
real 0m5.358s
user 0m5.040s
sys 0m0.257s

It seems that sharing a folder from host has a significant penalty.
Is it possible to optimise this? Somehow caching files in qemu?

[jklewa]

Relevant discussion and benchmarks of volume mount options with QEMU NixOS/nixpkgs#122420 (comment)