while trying this mongo command in ubuntu I am getting this error.
ritzysystem@ritzysystem-Satellite-L55-A:~$ mongo MongoDB shell version: 2.6.1
It is possible that the data directory for mongo specified in /etc/mongod.conf is not a valid path.
/etc/mongod.conf
Try rechecking the path if it really exists sudo vi /etc/mongod.conf and check dbPath.
sudo vi /etc/mongod.conf
dbPath