Drush Not recognizing it's in a drupal root
If your settings.php file is inside a directory named default, then Drush will find it whenever your current working directory is anywhere inside the document root.  However, if settings.php is in some other directory, then you must either cd to the directory that contains settings.php, or identify your site via some other technique -- for example, by specifying --uri=mysite.com, or by using a Drush site alias.