CentOS下忘记MySql的root密码解决方案

转载：http://www.centoscn.com/mysql/2014/0603/3081.html

1．首先确认服务器出于安全的状态，也就是没有人能够任意地连接MySQL数据库。因为在重新设置MySQL的root密码的期间，MySQL数据库完全出于没有密码保护的状态下，其他的用户也可以任意地登录和修改MySQL的信息。可以采用将MySQL对外的端口封闭，并且停止Apache以及所有的用户进程的方法实现服务器的准安全状态。最安全的状态是到服务器的Console上面操作，并且拔掉网线。

2．修改MySQL的登录设置：
[root@CentOS ~]# vi /etc/my.cnf
在[mysqld]的段中加上一句：skip-grant-tables
例如：
[mysqld]
skip-grant-tables
datadir=/var/lib/mysql
socket=/var/lib/mysql/mysql.sock
user=mysql
# Disabling symbolic-links is recommended to prevent assorted security risks
symbolic-links=
保存并且退出vi。

3．重新启动mysqld
[root@CentOS ~]# service mysqld restart
Stopping mysqld:                                           [  OK  ]
Starting mysqld:                                           [  OK  ]

4．登录并修改MySQL的root密码
[root@CentOS ~]# /usr/bin/mysql
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 2
Server version: 5.1.69 Source distribution

Copyright (c) 2000, 2013, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

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

mysql> USE mysql;
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A

Database changed
mysql> UPDATE user SET Password = password ( 'NewPassword' ) WHERE User = 'root' ;
Query OK, 3 rows affected (0.00 sec)
Rows matched: 3  Changed: 3  Warnings: 0

mysql> flush privileges;
Query OK, 0 rows affected (0.00 sec)

mysql> quit
Bye

5．将MySQL的登录设置修改回来
[root@CentOS ~]# vi /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vi。

6．重新启动mysqld
[root@CentOS ~]# service mysqld restart
Stopping mysqld:                                           [  OK  ]
Starting mysqld:                                           [  OK  ]