MariaDB Warning: 'root@localhost' has both … The password will be ignored

Question

I have installed MariaDB on Ubuntu LTS 16.04. Then I have run

/usr/bin/mysql_secure_installation

and set a root password. Accessing the DB via

Answer 1

It is normal, if by saying "accessing the DB via mysql -u root -p works fine" you mean that you are running it while being a system root (or under sudo). You should not be able to do it as an ordinary user.

Packages generated by Ubuntu by default have unix_socket authentication for the local root. To check, run

SELECT user, host, plugin FROM mysql.user;

You should see unix_socket in the plugin column for root@localhost.

If you want to use the password authentication instead, run

UPDATE mysql.user SET plugin = '' WHERE plugin = 'unix_socket';
FLUSH PRIVILEGES;