1．修改MySQL的登录设置： 

# vim /etc/my.cnf 

在[mysqld]的段中加上一句：skip-grant-tables 

例如： 

[mysqld] 

datadir=/var/lib/mysql 

socket=/var/lib/mysql/mysql.sock 

skip-grant-tables 

保存并且退出vi。

2．重新启动mysqld 

# service mysqld restart 

Stopping MySQL: [ OK ] 

Starting MySQL: [ OK ]

3．登录并修改MySQL的root密码 

# mysql 

Welcome to the MySQL monitor. Commands end with ; or \g. 

Your MySQL connection id is 3 to server version: 3.23.56 

Type 'help;' or '\h' for help. Type '\c' to clear the buffer. 

mysql> USE mysql ; 

Database changed 

mysql> UPDATE user SET Password = password ( 'new-password' ) WHERE User = 'root' ; 

Query OK, 0 rows affected (0.00 sec) 

Rows matched: 2 Changed: 0 Warnings: 0 

mysql> flush privileges ; 

Query OK, 0 rows affected (0.01 sec) 

mysql> quit

5．将MySQL的登录设置修改回来 

# vim /etc/my.cnf 

将刚才在[mysqld]的段中加上的skip-grant-tables删除 

保存并且退出vim

6．重新启动mysqld 

# service mysqld restart 

Stopping MySQL: [ OK ] 

Starting MySQL: [ OK ]