Install and Run MongoDB on Mac

A simple step-by-step guide to get mongoDB on your Mac:
-including some problems I faced and the solutions that worked for me.

In a perfect world, these 7 steps should work for you. I envy you if they do. If they don’t, you’re in good company. I have included multiple sources and solutions that I found while experiencing hours worth of issues. I hope I save you multiple hours of frustration!

Step 1:
Install Homebrew
-paste the command below in your macOS terminal

/bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)"

Step 2:
Install mongoDB

brew install mongodb

Step 3:
Create the db directory***

mkdir -p /data/db

Step 4:
Give permissions for /data/db directory

sudo chown -R `id -un` /data/db
# (enter password)

• ** This command will not work if you are running macOS Catalina or newer, see problems/solution section for fix.

Step 5:
Run the Mongo daemon
-this will start the mongo server

mongod

Step 6:
Run the mongo shell
-while the Mongo daemon (mongod) is running, open another terminal and run

mongo

Step 7:
When finished, make sure to exit Mongo

quit() or exit

and stop the Mongo daemon

*ctrl-c*

It is important to close out of the Mongo shell anytime you aren’t actively using it. This is because if mongoDB does not shutdown correctly (power outage, accidental unplug, etc.) it could lead to data corruption.

Problems and their Solutions

maybe

Next up is a look at each step and the errors I faced on each.

Step 1 issue(s):
I did not face any errors when installing Homebrew. This was certainly the easiest part for me, personally.
Here is a link to the Homebrew Issues Documenation

Step 2 issue(s):
I received a few errors that went something like:
“error no formulae found in taps”.

Once I found the right Stack Overflow question the solution was discovered.
Each line is a different command*

brew tap mongodb/brew
brew install mongodb-community
brew services start mongodb-community

Step 3/4 issue(s):
macOS Catalina and newer: the root folder is no longer writable.
This is the cause of the “read-only file system” error.

sudo mkdir -p /System/Volumes/Data/data/db

give this permissions:

sudo chown -R user_id:user_name /System/Volumes/Data/data/db
example below. the user_id = blankenstein.dev and the user_name = admin because that is my user status on this computer.

Step 5 issue(s):
Running the mongoDB daemon

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

Step 6 issue(s):
Running the mongoDB shell

If running

mongo

give you an error

admin@Admins-MacBook-7 ~ % mongo
MongoDB shell version v4.4.3
connecting to: mongodb://127.0.0.1:27017/?compressors=disabled&gssapiServiceName=mongodb
Error: couldn't connect to server 127.0.0.1:27017, connection attempt failed: SocketException: Error connecting to 127.0.0.1:27017 :: caused by :: Connection refused :
connect@src/mongo/shell/mongo.js:374:17
@(connect):2:6
exception: connect failed
exiting with code 1
admin@Admins-MacBook-7 ~ %

Double check to make sure that you are running the daemon.
mongod must be running before you try to run the shell.

Other issue(s):

A possible quick fix to the daemon throwing a
“fassert() failure” error could be to :

turn it off and turn it back on again

brew services stop mongodb-community
then
brew services start mongodb-community

Live troubleshooting document:

I plan on keeping this document updated as I run into problems or if I am ever asked to help solve a problem that isn’t already on this list.

Resources

mongoDB docs exit code and statuses

Install mongoDB Community on macOS using .tgz Tarball

treehouse.github.io installation instructions

mongoDB macOS installation instructions

Stack Overflow solution: Read-only file system when attempting mkdir