MongoDB

MongoDB is a database used to manage and create databases.

Useful commands

Completely uninstall MongoDB

If you've messed up your MongoDB installation and want to completely uninstall use these commands:

1. sudo service mongod stop
2. sudo apt-get purge mongodb-org*
3. sudo rm -r /var/log/mongodb
4. sudo rm -r /var/lib/mongodb

Issues

MongoDB fails to start

When running the command sudo systemctl status mongod the MongoDB server will fail to start with the message (code=exited, status=62)

Solution

Attempt to repair the MongoDB installation by running the command:

sudo mongod --repair

If this command fails and it shows the error Data directory /data/db not found create the directory using this command:

sudo mkdir -p /data/db

Then restart mongodb:

1. sudo systemctl stop mongod
2. sudo systemctl start mongod
3. sudo systemctl status mongod

MongoDB fails to start immediately after installation

When running the command sudo systemctl start mongod an error will appear saying:

Failed to start mongod.service: Unit mongod.service not found.

Solution

Enter the command:

sudo systemctl enable mongod

This will link the service and allow it to start.