Cannot restart mongodb - mongodb

Question

I am trying to restart my mongodb but it has an error
this is the error:
[root#testdb vagrant]# sudo service mongod restart
Stopping mongod: [FAILED]
Starting mongod: warning: bind_ip of 0.0.0.0 is unnecessary; listens on all ips by default
about to fork child process, waiting until server is ready for connections.
forked process: 6843
ERROR: child process failed, exited with error number 100
[FAILED]
my config file is:
bind_ip = 0.0.0.0
dbpath = /var/lib/mongodb
fork = true
logappend = true
logpath = /var/log/mongodb/mongodb.log
nojournal = false
pidfilepath = /var/run/mongodb/mongodb.pid
port = 27017
rest = false
smallfiles = false
this is my log
this is the output of ps ax | grep mongod
1935 ? Sl 1:53 /usr/bin/mongod --config /etc/mongodb.conf
5592 pts/0 S+ 0:00 tail -f /var/log/mongodb/mongodb.log
5889 pts/1 S+ 0:00 grep mongod
i also removed /var/lib/mongodb/mongod.lock
when i restart this is the output stop failed.
Stopping mongod: [FAILED]
Starting mongod: warning: bind_ip of 0.0.0.0 is unnecessary; listens on all ips by default
about to fork child process, waiting until server is ready for connections.
forked process: 5874
child process started successfully, parent exiting
[ OK ]

Answer 1

Most likely either a permissions issue or a incorrect shutdown.
Run commands sudo rm /var/lib/mongodb/mongod.lock to remove the lock on mongod process then chown the directory to the mongod user using
chown-R mongod: mongod /var/lib/mongo
then start service sudo service mongod start

Answer 2

Before I try and give my input, here is the MongoDB documentation for processes:
http://docs.mongodb.org/manual/tutorial/manage-mongodb-processes/#StartingandStoppingMongo-SendingshutdownServer%28%29messagefromthemongoshell
That being said, trying shutting down the server:
use admin
db.shutdownServer()
and starting it again.
If you're using linux:
mongod --shutdown
I hope this helped a little, or atleast you can try and use the documentation.