Most of the time it's PHP unable to connect to the database. Check your PHP error logs and see if it gives you a hint.

Jamie Holly
http://www.intoxination.net 
http://www.hollyit.net

On 1/6/2011 1:14 PM, Ryan LeTulle wrote:

Training users on a new Drupal site today and getting lots of site offline errors. Can someone tell me what triggers this? PHP memory setting?

Ryan LeTulle, Web Developer

blog: bayousoft.com
twitter: @bayousoft