I have searched all over but couldn't find where service mysqld restart picks up the configuration file from:
sudo find / -name "*.cnf" | grep my /usr/share/doc/mysql-community-server-5.6.33/my-default.cnf /usr/share/mysql/my-default.cnf /var/lib/mysql/auto.cnf /var/lib/mysql/my.cnf /etc/my.cnf
My MySQL 5.6.33 is running on 1 GB of InnoDB Buffer Pool whereas none of these files has that setting. I have setting
[mysqld] innodb_buffer_pool_size = 4G
in the file copied from /usr/share/mysql/my-default.cnf to /etc/my.cnf - I did this:
service mysqld restart --defaults-file=/etc/my.cnf
Still not working.