MongoDB only works when run as root on Ubuntu - data directory issue

Question

I installed MongoDB with the official packages (mongodb-stable), and followed the Quickstart guide which includes:

By default MongoDB will store data in /data/db, but it won't automatically create that directory. To create it, do:

$ sudo mkdir -p /data/db/
$ sudo chown `id -u` /data/db

You can also tell MongoDB to use a different data directory, with the --dbpath option.

MongoDB will only start if I run sudo mongod - if I try and run just mongod I get the error:

Mon Mar 14 15:27:07 [initandlisten] couldn't open /data/db/test.ns errno:13 Permission denied
Mon Mar 14 15:27:07 [initandlisten]   couldn't open file /data/db/test.ns terminating
Mon Mar 14 15:27:07 dbexit:

What gives?

Solution 1

You created /data/db as root so it has those permissions. You can change the permissions to your user account, or whatever you have mongo running as.

chown -R username /data/db

or /data

You can also set a group

chown -R username.groupname

The -R does it recursively, so it will affect all the files you've created running mongoDB as root already.

Solution 2

I just had the same issue on RHEL 8, in year 2021.

I could run sudo mongod with sudo privileges but could not start it as a service with: sudo systemctl start mongod.

I tried many solutions and tested after each attempt, what ultimately solved it for me is changing ownership of /data/db/, /var/lib/mongo/, and /var/log/mongodb/ to mongod.

exact commands:

sudo chown -R mongod:mongod /var/lib/mongo/
sudo chown -R mongod:mongod /var/log/mongodb/
sudo chown -R mongod:mongod /data/

Comments

[Emmanuel M. Smith]

Any benefit to leaving the owner as root and just assigning a group? Or is it better to specifically set the owner as a user?

[Aaron]

Thanks, I was chowning the directory to mongodb:mongodb instead of my username:my group.

[Mathias Haugsbø]

Remember that you maybe have to run sudo infront of chown -R username /data/db