問題描述：
centos 安裝MySQL
$yum install mysql-server
安裝之后執行命令mysql
報錯：
查看mysql的啟動日志：
[ERROR] InnoDB: auto-extending data file ./ibdata1 is of a different size 640 pages (rounded down to MB) than specified in the .cnf file: initial 768 pages, max 0 (relevant if non-zero) pages!
2016-02-22 23:02:55 29830 [ERROR] InnoDB: Could not open or create the system tablespace. If you tried to add new data files to the system tablespace, and it failed here, you should now edit innodb_data_file_path in my.cnf back to what it was, and remove the new ibdata files InnoDB created in this failed attempt. InnoDB only wrote those files full of zeros, but did not yet use them in any way. But be careful: do not remove old data files which contain your precious data!
2016-02-22 23:02:55 29830 [ERROR] Plugin 'InnoDB' init function returned error.
2016-02-22 23:02:55 29830 [ERROR] Plugin 'InnoDB' registration as a STORAGE ENGINE failed.
2016-02-22 23:02:55 29830 [ERROR] Unknown/unsupported storage engine: InnoDB
2016-02-22 23:02:55 29830 [ERROR] Aborting
解決方法：
執行刪除命令：rm -rf /var/lib/mysql/ib*
刪除：ibdata1、ib_logfile0、ib_logfile1文件
重新啟動：service mysqld start