sudo mongod
I had the following error message:
I've highlighted the important error message in red.2017-03-15T09:05:27.963+1100 I CONTROL [initandlisten] MongoDB starting : pid=1347 port=27017 dbpath=/data/db 64-bit host=mongodb-node-3.novalocal 2017-03-15T09:05:27.963+1100 I CONTROL [initandlisten] db version v3.2.5 2017-03-15T09:05:27.963+1100 I CONTROL [initandlisten] git version: 34e65e5383f7ea1726332cb175b73077ec4a1b02 2017-03-15T09:05:27.963+1100 I CONTROL [initandlisten] OpenSSL version: OpenSSL 1.0.1e-fips 11 Feb 2013 2017-03-15T09:05:27.963+1100 I CONTROL [initandlisten] allocator: tcmalloc 2017-03-15T09:05:27.963+1100 I CONTROL [initandlisten] modules: none 2017-03-15T09:05:27.963+1100 I CONTROL [initandlisten] build environment: 2017-03-15T09:05:27.963+1100 I CONTROL [initandlisten] distmod: rhel70 2017-03-15T09:05:27.963+1100 I CONTROL [initandlisten] distarch: x86_64 2017-03-15T09:05:27.963+1100 I CONTROL [initandlisten] target_arch: x86_64 2017-03-15T09:05:27.963+1100 I CONTROL [initandlisten] options: {}
2017-03-15T09:05:27.985+1100 I STORAGE [initandlisten] exception in initAndListen: 29 Data directory /data/db not found., terminating
2017-03-15T09:05:27.985+1100 I CONTROL [initandlisten] dbexit: rc: 100
It appears mongo was completely ignoring my configured dbpath specified in the /etc/mongod.conf.
So what was going on?
Turns out that mongo's journal folder got corrupted when the server immediately shutdown. So removing /var/lib/mongo/journal folder solved the problem.
Then I restarted mongod and that got everything back up and running again!
Reference: http://stackoverflow.com/questions/20729155/mongod-shell-doesnt-start-data-db-doesnt-exsist