Easy Question - In 2 Much of A Rush it Figure it out

[Datacide]

$filename = $_SERVER['DOCUMENT_ROOT'] . '/includes/pages/whatsnew.txt';
$fp = fopen($filename, "w+");
$write = fputs($fp, $file);
fclose($fp); 

Error:

Warning: fopen(/home/groups/htdocs/includes/pages/whatsnew.txt): failed to open stream: Read-only file system in /home/groups/htdocs/admin/1.php on line 4.

I set the file and the directory to 777, so why is it still b1tchin?