$_SESSION['form'] being bloated

I looked at form.inc. It seems to unset the $_SESSION['form'][$form_build_id] *one day* after the form was created (in _drupal_clean_form_sessions()). Is there a known issue with limited session variable size?

This could be related to the VBO variables holding all actions' information, which is huge. I am considering storing the settings in a DB table instead.

The session info has to be unserialized and appended to the $user object on every page view so it is very bad to have huge variables in $_SESSION. If you need them, please unset them as soon as possible.

@moshe: I don't store anything in $_SESSION directly. I store the VBO settings in the variables table, but each setting is a huge string that could reach tens of KBs. Maybe you could confirm that such big variables could bloat $_SESSION.

Variables has the same problem settings. They get unserialized on every page view. I am not too familiar with what is being stored so I can't really suggest an alternative. if you really need that much data, using own table is a good option. It can even be a copy of the variables schema but one that only gets read when you are on a VBO page.

Fixed as suggested by moshe.