安装报错， 求解？

安装报错了。 

Warning: Cannot modify header information - headers already sent by (output started at /data/carbon/install/index.php:1) in /data/carbon/library/PDO.class.php on line 229

Warning: Cannot modify header information - headers already sent by (output started at /data/carbon/install/index.php:1) in /data/carbon/library/PDO.class.php on line 230
Unhandled Exception. 
SQLSTATE[HY000] [2002] No such file or directory
You can find the error back in the log.

填完数据库账号的时候， 点击安装。报了这个错误， 是什么问题呢。