MySQL Reference Manual :: A.3.2 How to Run MySQL as a Normal User

Stop the server if it's running (use mysqladmin shutdown).

Change the database directories and files so that user_name has privileges to read and write files in them (you might need to do this as the Unix root user):

shell> chown -R user_name /path/to/mysql/datadir

If you do not do this, the server is not able to access databases or tables when it runs as user_name.

If directories or files within the MySQL data directory are symbolic links, you'll also need to follow those links and change the directories and files they point to. chown -R might not follow symbolic links for you.

Start the server as user user_name. If you are using MySQL 3.22 or later, another alternative is to start mysqld as the Unix root user and use the --user=user_name option. mysqld starts up, then switches to run as the Unix user user_name before accepting any connections.

To start the server as the given user automatically at system startup time, specify the username by adding a user option to the [mysqld] group of the /etc/my.cnf option file or the my.cnf option file in the server's data directory. For example:

[mysqld]
user=user_name