网上有很多关于Mac os 安装MAMP PRO后出现数据库无法启动的故障处理办法，然而每个都试了，完全不能解决问题，错误提示是：

InnoDB: The error means the system cannot find the path specified.

InnoDB: If you are installing InnoDB, remember that you must create

InnoDB: directories yourself, InnoDB does not create them.

InnoDB: Error: could not open single-table tablespace file ./mysql/slave_relay_log_info.ibd

InnoDB: We do not continue the crash recovery, because the table may become

InnoDB: corrupt if we cannot apply the log records in the InnoDB log to it.

InnoDB: To fix the problem and start mysqld:

InnoDB: 1) If there is a permission problem in the file and mysqld cannot

InnoDB: open the file, you should modify the permissions.

InnoDB: 2) If the table is not needed, or you can restore it from a backup,

InnoDB: then you can remove the .ibd file, and InnoDB will do a normal

InnoDB: crash recovery and ignore that table.

InnoDB: 3) If the file system or the disk is broken, and you cannot remove

InnoDB: the .ibd file, you can set innodb_force_recovery > 0 in my.cnf

InnoDB: and force InnoDB to continue crash recovery here.

170324 11:18:41 mysqld_safe mysqld from pid file /Applications/MAMP/tmp/mysql/mysql.pid ended

出现这个情况是之前已经安装过MAMP PRO，从倒数第三行的提示来看需要修改my.cnf，使用mamp打开mysql是可以正常启动的，但是Hosts无法修改路径及配置多个测试域名，每次都要去修改一大堆东西，很不方便，下面我们来解决MAMP PRO mysql无法启动的问题；

其实原因初步判断应该是在MAMP PRO的应用管理端，从应用程序管理文件夹，找到MAMP PRO，显示包内容，完成访问路径/Applications/MAMP PRO/MAMP PRO.app/Contents/Resources/my.cnf，复制你对应版本的my.cnf文件到桌面，修改innodb force recovery=2；将原来的备份，替换对应版本的my.cnf，修改完成回到MAMP PRO控制面板，点击mysql，成功启动！

最后来张成功启动的截图，有图有真相！