Mac fills up CIRCUITPY drives and how to fix

By | August 18, 2026

When i create files for mp3 files on my CIRCUITPY drive and make changes the drive fills up faster than it should. When I inspect the drive on a PC I see lots of hidden files.

What I am seeing are macOS metadata files. These files are often as big as the original file. Which results in halving my drive space.

  • ._filename.mp3
  • ._filename.wav
  • ._anything
  • .DS_Store

To clean them off I use this set of commands in the terminal.

find /Volumes/CIRCUITPY -name '._*' -delete
find /Volumes/CIRCUITPY -name '.DS_Store' -delete