一、停止MySQL（如果处于运行状态）

#service mysqld stop

输出

Shutting down MySQL.? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? [? OK? ]

二、启动MySQL_safe，如此以来便可不用密码登录MySQL

# mysqld_safe --skip-grant-tables &

输出类似

Starting mysqld daemon with databases from /var/lib/mysql
mysqld_safe[6025]: started

三、登录MYSQL

# mysql -u root

输出

Welcome to the MySQL monitor.? Commands end with ; or \g.
Your MySQL connection id is 1 to server version: 4.1.15-Debian_1-log
Type 'help;' or '\h' for help. Type '\c' to clear the buffer.
mysql>

四、设置新密码

mysql> use mysql;
mysql> update user set password=PASSWORD("NEW-ROOT-PASSWORD") where User='root';
mysql> flush privileges;
mysql> quit

五、停止MySQL

# /etc/init.d/mysql stop

输出

Stopping MySQL database server: mysqld
STOPPING server from pid file /var/run/mysqld/mysqld.pid
mysqld_safe[6186]: ended
[1]+? Done? ? ? ? ? ? ? ? ? ? mysqld_safe --skip-grant-tables

六、启动MySQL并测试新密码是否正确

# /etc/init.d/mysql start
# mysql -u root -p