Large file upload guidelines I have a site built in Drupal 7.23, which is supposed to handle large files uploads to it. 

I have a node form with 5 File upload fields which is supposed to take 200MB files for each. 

What should be the Apache server adjustments that i need to taken in favour of making the upload process seamlessly? 

Also i have Video module with FFMPEG configured to convert on cron. Someday I got message form server support team that my FFMPEG is taking 100% CPU. 

Also i got some MySQL errors, like Lock TimeOut etc. what to do ?

Please let me know an optimal settings for these kind of server which runs Drupal.
It is normal for the CPU usage to be at 100% when FFMPEG runs. Video compression is a computationally difficult task.

See this related question. If you have a two core VPS then you could make sure that FFMPEG only uses one core and thus always leaves at least one core for Apache/PHP/MySQL.

I created a similar site and it generally worked but it certainly had the occasional errors. It was a 4-core VPS and when transcoding all four cores were often at 100%. If I were to design the site again I think I would use a video transcoding service such as Amazon's Elastic Transcoder. Making sure FFMPEG would recognize all the different file encodings especially MP4 was quite a pain.