I got an error about dbpath (/data/db/) does not exist, but /etc/mongodb.conf named it dbpath = /var/lib/mongodb. So, which is the de
dbpath (/data/db/) does not exist
/etc/mongodb.conf
dbpath = /var/lib/mongodb.
For a Windows machine start the mongod process by specifying the dbpath:
mongod
mongod --dbpath \mongodb\data
Reference: Manage mongod Processes