Resetting the Root Password on Unix/Linix Systems

Log on to your system as the Unix mysql user that the mysqld server runs as.

Locate the .pid file that contains the server's process ID. The exact location and name of this file depend on your distribution, host name, and configuration. Common locations are /var/lib/mysql/, /var/run/mysqld/, and /usr/local/mysql/data/. Generally, the file name has an extension of .pid and begins with either mysqld or your system's host name.

You can stop the MySQL server by sending a normal kill (not kill -9) to the mysqld process, using the path name of the .pid file in the following command:

shell> kill `cat /mysql-data-directory/host_name.pid`

Note the use of backticks rather than forward quotes with the cat command; these cause the output of cat to be substituted into the kill command.

Create a text file and place the following statements in it. Replace the password with the password that you want to use.

UPDATE mysql.user SET Password=PASSWORD('MyNewPass') WHERE User='root';
FLUSH PRIVILEGES;

The UPDATE and FLUSH statements each must be written on a single line. The UPDATE statement resets the password for all existing root accounts, and the FLUSH statement tells the server to reload the grant tables into memory.

Save the file. For this example, the file will be named /home/me/mysql-init. The file contains the password, so it should not be saved where it can be read by other users.

Start the MySQL server with the special --init-file option:

shell> mysqld_safe --init-file=/home/me/mysql-init &

The server executes the contents of the file named by the --init-file option at startup, changing each root account password.

After the server has started successfully, delete /home/me/mysql-init.

Reference: MySQL Manual