Read-only file system when attempting mkdir /data/db on Mac

Question

I am trying to create a new folder in the main directory

Tried all kinds of examples

sudo mkdir /data/db

sudo mkdir -p /data/db<

Answer 1

You can't create a folder on the root directory on Mac Catalina anymore!

https://www.apple.com/macos/catalina/features/

Dedicated system volume

macOS Catalina runs in a dedicated, read-only system volume — which means it is completely separate from all other data and helps improve the reliability of macOS.

# macOS Catalina, mkdir path
$ sudo mkdir -p /System/Volumes/Data/data/db

# give permissions
$ sudo chown -R `id -un` /System/Volumes/Data/data/db

# macOS 10.14.x -
$ sudo mkdir -p /data/db

# macOS 10.15.x +
$ sudo mkdir -p /System/Volumes/Data/data/db

refs

https://discussions.apple.com/thread/250720711

https://zellwk.com/blog/install-mongodb/

https://www.youtube.com/watch?v=DX15WbKidXY