Method to reset the mysql server root password in ubuntu

First stop mysql service:

 
root@webserver:/home/webmaster# service mysql stop 

Then create a new mysql service using the ignore password authentication mode:

 
root@webserver:/home/webmaster# mysqld --user=mysql --skip-grant-tables --skip-networking & 

Return PID and other startup information after successful startup

 
[1] 3591 
root@webserver:/home/webmaster# 121005 2:59:27 [Note] Plugin 'FEDERATED' is disabled. 
121005 2:59:27 InnoDB: The InnoDB memory heap is disabled 
121005 2:59:27 InnoDB: Mutexes and rw_locks use GCC atomic builtins 
121005 2:59:27 InnoDB: Compressed tables use zlib 1.2.3.4 
121005 2:59:27 InnoDB: Initializing buffer pool, size = 128.0M 
121005 2:59:27 InnoDB: Completed initialization of buffer pool 
121005 2:59:27 InnoDB: highest supported file format is Barracuda. 
121005 2:59:27 InnoDB: Waiting for the background threads to start 
121005 2:59:28 InnoDB: 1.1.8 started; log sequence number 1595685 
121005 2:59:28 [Note] mysqld: ready for connections. 
Version: '5.5.24-0ubuntu0.12.04.1' socket: '/var/run/mysqld/mysqld.sock' port: 0 (Ubuntu) 

Connect to mysql system library:

 
root@webserver:/home/webmaster# mysql -u root mysql 

After connecting to the mysql library, directly change the password of the root account to the new password 'mynewpasswd':

 
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement. 

mysql> update user set Password=PASSWORD('mynewpasswd') where user='root'; 
Query OK, 3 rows affected (0.00 sec) 
Rows matched: 3 Changed: 3 Warnings: 0 

mysql> FLUSH PRIVILEGES; 
mysql> quit; 
Bye 

Abort the mysql service process (see screen information for PID 3591 when starting the service) :

 
root@webserver:/home/webmaster# kill 3591 

Start mysql service normally and login mysql server with new password successfully:

 
root@webserver:/home/webmaster#service mysql start 
root@webserver:/home/webmaster#mysql -u root -pmynewpasswd