mongod shell doesn't start, data/db doesn't exsist

Question

When I start mongod trowed error. What is the problem?

root@cs12867:~# mongod
mongod --help for help and startup options
Sun Dec 22 15:37:44.081 [initandlist         


        

Answer 1

Another solution to that problem could be:

.

Delete the files inside of /data/journal/ or /data/db/journal/

.

Especially if your database stopped working after an unclean restart / crash. It seems that the journal files can get corrupted and block the mongo service from starting. Remember to backup the files first just in case.

Following these posts:

https://stackoverflow.com/a/16323101

https://jira.mongodb.org/browse/SERVER-5380

Answer 2

The default db path for mongodb is /data/db/.

So when you run:

mongod

MongoDB checks if /data/db/ is present and if the user has access to it. In your case, there is no such directory and hence the error.

However you can override the default db path using the --dbpath argument of mongod( or use a config file).

mongod --dbpath /var/lib/mongodb/data/db

In this case instead of checking for /data/db/ mongoDB check for /var/lib/mongodb/data/db. In your case, you have the specified directory and you have access to it and hence it runs.

And doing this doesn't start the mongo shell. To start the shell, start mongod first as mentioned above and leave it running. Then in another terminal execute

mongo

This will start the mongo shell.

Answer 3

As I see from the problem that creating the data/db directory will fix your problem.

Create that and then add like this if you have directory path in c drive.

mongod --dbpath "c://data/db"

After setting the dbpath you should start the mongodb as service.

sudo service mongodb start