mysql 配置文件目录：/etc/my.cnf

root 密码为空的时候配置文件中下面这句：

skip-grant-tables

GRANT ALL PRIVILEGES ON *.* TO IDENTIFIED BY '123' WITH GRANT OPTION;

执行这句时候错误：

ERROR 1290 (HY000): The MySQL server is running with the --skip-grant-tables option so it cannot execute this statement

这个时候我们只需要

flush privileges
一下，在添加用户就OK了，

mysql> flush privileges;
Query OK, 0 rows affected (0.01 sec)

mysql> GRANT ALL PRIVILEGES ON . TO IDENTIFIED BY '123' WITH GRANT OPTION;
Query OK, 0 rows affected (0.00 sec)

这个时候我们成功搞定了，再登录就可以了。

如果报错如下信息：

Error: Cannot retrieve repository metadata (repomd.xml) for repository: InstallMedia. Please verify its path and try again
You could try using --skip-broken to work around the problem
You could try running: rpm -Va --nofiles --nodigest

我们只要到/etc/yum.repo.s下面把packetxxxx.repo和redhat.repo两个文件删除掉，再启动就可以了，