而这个问题居然也很常见！
要修改MySQL的root密码，有两个先决条件：
- 有修改MySQL配置文件的权限
- 有重启MySQL服务的权限
先修改配置文件：
引用
# vim /etc/my.cnf
[mysqld]
datadir=/var/lib/mysql
socket=/var/lib/mysql/mysql.sock
user=mysql
# Default to using old password format for compatibility with mysql 3.x
# clients (those using the mysqlclient10 compatibility package).
old_passwords=1
# Disabling symbolic-links is recommended to prevent assorted security risks;
# to do so, uncomment this line:
# symbolic-links=0
[mysqld_safe]
log-error=/var/log/mysqld.log
pid-file=/var/run/mysqld/mysqld.pid
在 [mysqld]下增加 skip-grant-tables，即跳过权限验证。
然后登录MySQL，修改root密码：
引用
# mysql
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 3
Server version: 5.0.95 Source distribution
Copyright (c) 2000, 2011, 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('<Your Password>') 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
然后把刚才修改的配置文件再改回来，最后重启服务：
引用
# service mysqld restart
停止 MySQL： [确定]
启动 MySQL： [确定]
大功告成！
PS：更果断的办法：
引用
关闭mysqld
命令行执行 mysqld --skip-grant-tables & 无密码登陆！
突然了解了，黑客入侵，就这么简单。。。。