linux下mysql的root密码忘记解决方法
验证环境：
[root@localhost ~]# rpm -qa | grep mysql
mysql-5.1.71-1.el6.i686
mysql-server-5.1.71-1.el6.i686
mysql-libs-5.1.71-1.el6.i686
[root@localhost ~]# lsb_release -a
LSB Version: :core-4.0-ia32:core-4.0-noarch:graphics-4.0-ia32:graphics-4.0-noarch:printing-4.0-ia32:printing-4.0-noarch
Distributor ID: CentOS
Description: CentOS Linux release 6.0 (Final)
Release: 6.0
Codename: Final
[root@localhost ~]# uname -r
2.6.32-71.el6.i686
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：
# vi /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。
3．重新启动mysqld
# /etc/init.d/mysqld restart
Stopping MySQL: [ OK ]
Starting MySQL: [ OK ]
4．登录并修改MySQL的root密码
[root@localhost ~]# mysql
Welcome to the MySQL monitor. Commands end with ; or \\g.
Your MySQL connection id is 3
Server version: 5.1.71 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>UPDATE mysql.user SET Password = password ("new-password") WHERE User = 'root';
Query OK, 3 rows affected (0.00 sec)
Rows matched: 3 Changed: 3 Warnings: 0
mysql> exit
Bye
5．将MySQL的登录设置修改回来
# 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．再次重新启动mysqld
# /etc/init.d/mysqld restart
Stopping MySQL: [ OK ]
Starting MySQL: [ OK ]
参考网上资料：http://www.cnblogs.com/allenblogs/archive/2010/08/12/1798247.html
