Last_Errno: 1396

从库报错：
Last_Errno: 1396
                   Last_Error: Error 'Operation RENAME USER failed for 'maxscalemon'@'192.168.4.0'' on query. Default database: ''. Query: 'RENAME USER 'maxscalemon'@'192.168.4.0' TO 'maxscalemon'@'192.168.4.%''


解决：
从库上：
/etc/init.d/mysql stop
cd /home/mysql/data/
mkdir /mnt/data
mv * /mnt/data/


把主库的
cd /home/mysql/data/
mysql performance_schema  scp过来从库上的/home/mysql/data/里面
从库上
chown mysql.mysql -R /home/mysql/data/
/etc/init.d/mysql start