Interesting discovery with Drupal's file uploads today. We created a microsite that users can upload video to. These files could be 30MB or less... At first I believed this was a small change to our php.ini file on our server changing the following:

upload_max_filesize = 30M
post_max_size = 30M

I uploaded the file and yet I could still only upload a maximum of a 15M file. Completely perplexed, I asked my team to play with it to which they had no success. We scoured the Drupal documentation and found nothing and finally decided to crack open upload.module to see what the hell was going on.

Well as it turns out, the upload.module file does a 'silent sanity check' on post_max_size and literally cuts it in half (this makes almost no sense to us).

It was only then that we discovered this post on Drupal - http://drupal.org/node/104220

Changing the file to:

upload_max_filesize = 30M
post_max_size = 70M //double the value above

Worked just fine.