我通过位于 MySQL 站点中的包安装了 MySQL。
我改变了这个目录：
/usr/local/mysql-5.5.28-osx10.5-x86/data
为了_mysql
但是，当我尝试执行 mysqld start 时，我收到以下错误和警告：
121018 18:04:17 [Warning] Can't create test file /usr/local/mysql-5.5.28-osx10.5-x86/data/homer.lower-test
121018 18:04:17 [Warning] Can't create test file /usr/local/mysql-5.5.28-osx10.5-x86/data/homer.lower-test
121018 18:04:17 [Note] Plugin 'FEDERATED' is disabled.
mysqld: Can't find file: './mysql/plugin.frm' (errno: 13)
121018 18:04:17 [ERROR] Can't open the mysql.plugin table. Please run mysql_upgrade to create it.
121018 18:04:17 InnoDB: The InnoDB memory heap is disabled
121018 18:04:17 InnoDB: Mutexes and rw_locks use InnoDB's own implementation
121018 18:04:17 InnoDB: Compressed tables use zlib 1.2.3
121018 18:04:17 InnoDB: Initializing buffer pool, size = 128.0M
121018 18:04:17 InnoDB: Completed initialization of buffer pool
121018 18:04:17 InnoDB: Operating system error number 13 in a file operation.
InnoDB: The error means mysqld does not have the access rights to
InnoDB: the directory.
InnoDB: File name ./ibdata1
InnoDB: File operation call: 'create'.
InnoDB: Cannot continue operation.
关于可能发生的事情的任何提示？