MySQL does not start when upgrading OSX to Yosemite or El Capitan

Question

I know similar questions exist, such as MySQL with MAMP does not work with OSX Yosemite 10.10. However, I do have MAMP, nor XAMPP installed on my computer.

When I tr

Answer 1

I usually start mysql server by typing

$ mysql.server start

without sudo. But in error I type sudo before the command. Now I have to remove the error file to start the server.

$ sudo rm /usr/local/var/mysql/`hostname`.err