How can I set max size to upload files on passenger?
As far as I know, there is no way to directly do this in passenger, but the limit is based on the apache request body limit. So, you would need to edit your httpd.conf file and use LimitRequestBody to set it. You would need a VPS or dedicated server with us as well. Please see the top answer here with the solution for Apache: http://stackoverflow.com/questions/2200188/rails-file-upload-size-limit