Read-Only File System When Attempting Mkdir /Data/Db on Mac [Closed]

from the official docs

install homebrew and run the following commands

sudo chown -R $(whoami) $(brew --prefix)/*

then

brew tap mongodb/brew

then

brew install mongodb-community@4.2

and

brew services start mongodb-community

or

mongod --config /usr/local/etc/mongod.conf

then

ps aux | grep -v grep | grep mongod

and

mongo

to verify you can run show dbs in the mongo shell

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)

To make a permanent change of the path of mongod db folder.

Following these docs they say roughly this. If mongod is started with brew services:

$ brew services start mongodb-community@4.2

It will use config file at path /usr/local/etc/mongod.conf

To fix this, edit the config file:

$ vim /usr/local/etc/mongod.conf

And change the dbPath e.g. to your home directory like this:

systemLog:
  destination: file
  path: /usr/local/var/log/mongodb/mongo.log
  logAppend: true
storage:
  dbPath: /Users/<username>/data/db
net:
  bindIp: 127.0.0.1 

Save the file and restart mongod with brew:

$ brew services restart mongodb-community@4.2

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