$ sudo /etc/init.d/mysql stop
2、以不带权限的方式启动mysqld
$ sudo mysqld --skip-grant-tables &
3、以root身份访问mysql数据库
$ mysql -u root mysql
4、更新root用户的密码
UPDATE user SET Password=PASSWORD('NEWPASSWORD') WHERE User='root'; FLUSH PRIVILEGES; exit;
$ sudo /etc/init.d/mysql stop
$ sudo mysqld --skip-grant-tables &
$ mysql -u root mysql
UPDATE user SET Password=PASSWORD('NEWPASSWORD') WHERE User='root'; FLUSH PRIVILEGES; exit;