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

With macOS Catalina, you can no longer store files or data in the read-only system volume, nor can you write to the "root" directory ( / ) from the command line, such as with Terminal.

Answer 2

I did this:

mkdir -p usr/local/var/mongodb/data/db

since the new path that is "usr/local/var/mongodb".

Answer 3

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

Answer 4

Default Paths for the mongodb-community Formula

In addition to installing the MongoDB server and tool binaries, the mongodb-community formula creates:

• a configuration file: /usr/local/etc/mongod.conf
• a log directory path: /usr/local/var/log/mongodb
• a data directory path: /usr/local/var/mongodb

then it worked for me:

mkdir -p usr/local/var/mongodb/data/db

Answer 5

Mac version Catalina made the root folder is no longer writable.

Brew has an updated version of mongodb to use a new path (which it creates itself), /usr/local/var/mongodb and following these instructions will fix the issue:

Guide to installing updated mongodb-community-edition

brew install mongodb-community@VERSION where the first VERSION with the fix is 4.2

Answer 6

With the new macOS Catalina update, the folder /data/db becomes read-only, you cannot modify it. Follow this procedure to create a DB in another folder:

1. Change mongod directory :

   sudo mongod --dbpath /System/Volumes/Data/data/db

2. Give it an alias to use it as mongod:

   alias mongod="sudo mongod --dbpath /System/Volumes/Data/data/db"

3. Just type mongod in your terminal, it should work.

Extra => If you need to give it current user rights, use this line of code :

sudo chown -R $(whoami) /System/Volumes/Data/data/db

(Just for info -> $(whoami) is just a variable that returns your current user)