curl -O http://downloads.mongodb.org/osx/mongodb-osx-x86_64-2.6.7.tgz
cd /usr/share
sudo mkdir mongodb
chown -Rv {username} mongodb
cd mongodb
tar -zxvf ~/Downloads/mongodb-osx-x86_64-2.6.7.tgz
ln -s mongodb-osx-x86_64-2.6.7/ current
mkdir -p data/db
cd current
vi mongod.conf
Paste contents
Add export PATH=/usr/share/mongodb/current/bin:$PATH
to ~/.bash_profile
vi ~/Library/LaunchAgents/org.mongodb.mongod.agent.plist
Paste contents
cd /var/log/
sudo mkdir mongodb
sudo chown -Rv {username} mongodb
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On next login should launch mongodb