Is mongodb running?
check with either:
ps -edaf | grep mongo | grep -v grep # "ps" flags may differ on your OSor
/etc/init.d/mongodb status # for MongoDB version < 2.6 /etc/init.d/mongod status # for MongoDB version >= 2.6or
service mongod statusto see if mongod is running (you need to be root to do this, or prefix everything with sudo). Please note that the 'grep' command will always also show up as a separate process.
check the log file /var/log/mongo/mongo.log to see if there are any problems reported
For quickly checking if mongodb is running, this quick nc trick will let you know.
nc -zvv localhost 27017The above command assumes that you are running it on the default port on localhost.
For auto-starting it, you might want to look at this thread.