CentOS 下 重置MySQL密码的方法有很多，官网也提供了很方便的快捷操作办法，可参考资料 resetting permissions 。本文重置密码的具体步骤如下：
一、停止MySQL（如果处于运行状态）
#service mysqld stop
输出
Shutting down MySQL. [ OK ]
关于 #service mysqld stop 命令，可参考 CentOS 6.5 平台离线编译安装 MySQL 5.6.22。
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