Error:master and slave have equal MySQL server UUIDs

建立主从复制时，show slave status \G 发现报错如下：

Last_IO_Error: Fatal error: The slave I/O thread stops because master and slave have equal MySQL server UUIDs; these UUIDs must be different for replication to work.

查看 /etc/my.cnf 发现主从的 server_id = 值是不一样的。
[root@master1 home]# cat /etc/my.cnf | grep server_id
server_id = 1
[root@master2 mysqldata]# cat /etc/my.cnf | grep server_id
server_id = 2

查看show variables like 'server_id';值和my.cnf一致，没有错误。
(root@localhost) [(none)] show variables like 'server_id';
ERROR 2006 (HY000): MySQL server has gone away
No connection. Trying to reconnect...
Connection id:    7
Current database: *** NONE ***


+---------------+-------+
| Variable_name | Value |
+---------------+-------+
| server_id     | 2     |
+---------------+-------+
1 row in set (0.00 sec)

问题没有解决！！！

后来发现主从中auto.cnf文件的server-uuid一样造成的
[root@master2 mysqldata]# cat /home/opt/mysqldata/data/auto.cnf
[auto]
server-uuid=fa0d941d-f4ae-11e5-8911-000c2938ba5b

修改server-uuid，重启数据库即可正常。

Slave_IO_Running: Yes
            Slave_SQL_Running: Yes
...
Last_IO_Errno: 0
Last_IO_Error: 

造成server-uuid一样的原因是服务器之间直接复制了/home/opt/mysqldata/data这个文件。