Is there a way to use a generic 'Site is Down' page? I recently experienced issues with my hosting company and a few of my sites went down. All users could see was a standard Drupal PDO Exception page. Is there a way I can create/use a page to show a generic "we're having issues, please check back later" page instead of this if a major problem occurs?
Yes, it is quite simple. Just go to "admin/config/development/logging" and set "Error messages to display" to "none". You will then have only the error page with message "The website encountered an unexpected error. Please try again later.". The PDO exception will not be displayed.