My OS is Ubuntu 16.04.
And the ownerships along my files are:
for directories in / owned by root, apart from (as per directories around mongodb):

  • var/lib/mongodb owned by mongodb user
  • var/log/mongodb owned by mongodb user
  • I also noticed that /etc/mongod.conf is under root user, is this correct?

Then in my home directory all the files under /home/user/ are owned by user