Unable to start MongoDB after changing the data directory - mongodb

Question

I have installed with the help of following link: https://www.digitalocean.com/community/tutorials/how-to-install-mongodb-on-ubuntu-16-04
It was working fine by default. But when I change data directory in /etc/mongod.conf
#From
dbPath: /var/lib/mongodb
#To
dbPath: /media/user/'Mounted Volume'/mongodb_data
I am unable to start MongoDB. Following is the error message
$mongo
MongoDB shell version: 3.2.11
connecting to: test
2017-01-06T00:57:01.472+0530 W NETWORK [thread1] Failed to connect to 127.0.0.1:27017, reason: errno:111 Connection refused
2017-01-06T00:57:01.472+0530 E QUERY [thread1] Error: couldn't connect to server 127.0.0.1:27017, connection attempt failed :
connect#src/mongo/shell/mongo.js:229:14
#(connect):1:6
exception: connect failed
Following is the status
$ sudo systemctl status mongodb
mongodb.service - High-performance, schema-free document-oriented database
Loaded: loaded (/etc/systemd/system/mongodb.service; enabled; vendor preset:
Active: failed (Result: exit-code) since Fri 2017-01-06 00:56:40 IST; 7s ago
Process: 5735 ExecStart=/usr/bin/mongod --quiet --config /etc/mongod.conf (cod
Main PID: 5735 (code=exited, status=100)
Jan 06 00:56:40 GL552VW systemd[1]: Started High-performance, schema-free docume
Jan 06 00:56:40 GL552VW systemd[1]: mongodb.service: Main process exited, code=e
Jan 06 00:56:40 GL552VW systemd[1]: mongodb.service: Unit entered failed state.
Jan 06 00:56:40 GL552VW systemd[1]: mongodb.service: Failed with result 'exit-co
I am new to MongoDB. Maybe I am missing something very simple.

Answer 1

From the MongoDB config file documentation page
The Linux package init scripts included in the official MongoDB packages depend on specific values for systemLog.path, storage.dbpath, and processManagement.fork. If you modify these settings in the default configuration file, mongod may not start.
So if you modify these properties in the configuration file, you most probably have to write a new init script.