I was trying to use TokuMX, so I did:
sudo mongod --config /etc/tokumx.conf
and it just takes forever, and no response.
My TokuMX once worked fine. Everything broke when I upgraded MongoDB.
Any suggestions?
----------------------EDIT----------------------
Problem solved by re-installed TokuMX following https://github.com/Tokutek/mongo/wiki/Migrating-Single-Server
Thanks everyone!