My site, which was running 2.9.x, was delivering a blank page today. In the past, I've found that getting the current version was the first step to debugging.
So, I decided to start by upgrading to the current version of EE. After following the directions and clicking on the Upgrade button, I received the following error:
Error Number: 1 Can't create/write to file '/tmp/#sql_26a4_0.MYI' (Errcode: 30) SHOW COLUMNS FROM `exp_sessions` Filename: /home/bp/public_html/ee_cms/expressionengine/libraries/Smartforge.php Line Number: 122
Oh, crap. Please help.