在安装MySQL时，随便设了一个密码，现在怎么也想不起来了，只好重设MySQL的root密码。

在网上搜到一篇文章：Resetting a forgotten MySQL root password，按照文章里的办法恢复成功。把步骤记录如下。

首先停止MySQL服务：
# service mysqld stop

接下来，使用mysqld_safe命令在后台启动MySQL服务器，这里使用了–skip-grant-tables选项，允许不使用密码连接MySQL数据库：
# /usr/bin/mysqld_safe --skip-grant-tables &
[1] 5933
nohup: ignoring input and redirecting stderr to stdout
Starting mysqld daemon with databases from /var/lib/mysql
mysqld_safe[5972]: started

接下来，登录数据库，并更新root用户的密码：
# mysql -u root mysql
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A

Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 1
Server version: 5.1.56

Type 'help;' or '\h' for help. Type '\c' to clear the buffer.

mysql> update user set Password=PASSWORD('new-password-here') 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> exit
Bye

现在，把mysqld_safe切换到前台，并使用CTRL-C结束它的运行：
# fg
/usr/bin/mysqld_safe --skip-grant-tables
^C
STOPPING server from pid file /var/run/mysqld/mysqld.pid
mysqld_safe[6005]: ended

然后重新启动MySQL服务：
# service mysqld start
Starting MySQL database server: mysqld.
Checking for corrupt, not cleanly closed and upgrade needing tables..

现在，就可以使用新设置的root连接数据库了：
# mysql -u root -p
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 681
Server version: 5.1.56

Type 'help;' or '\h' for help. Type '\c' to clear the buffer.

mysql> quit
Bye