现象：
centos服务器异常断电mysql启动异常启动Mysql时报错：mysqld_safe mysqld from pid file /usr/local/mysql/Linux.pid end
但是打开日志文件 查看
InnoDB: Completed initialization of buffer pool
InnoDB: Error: log file ./ib_logfile0 is of different size 50331648 bytes
InnoDB: than specified in the .cnf file 5242880 bytes!
160603
[ERROR] Plugin ‘InnoDB’ init function returned error.
160603
14:06:15 [ERROR] Plugin ‘InnoDB’ registration as a STORAGE ENGINE failed.
160603
14:06:15 [ERROR] Unknown/unsupported storage engine: InnoDB
160603 14:06:15 [ERROR] Aborting
处理方案：
1、存储引擎错误
Unknown/unsupported storage engine: InnoDB
2、检查一下配置文件中关于innodb的参数，如果有skip-innodb注释掉
3、如果重新设置了innodb_log_file_size之类的，
4、需要删除几个rm -rf ib_logfile，然后重启数据库