Today encounter a strange question, mongodbd open safety certification, which added /etc/mongod.conf
security:
authorization:enabled
After, service mongod start can not always start mongodb, and there is no error, no output any Log, but by mongod -auth it can start, but after such a start, they can not use the user login authentication through, and finally spent a lot of time before Find:
TMBD, and in enabled: between, there must be a space, that is,
security:
authorization: enabled
Finally smooth start