title: What is the best approach to handle large file uploads in a rails app?
body: <p>I am interested in understanding the different approaches to handling large file uploads in a Rails application, 2-5Gb files.</p>
  
  <p>I understand that in order to transfer a file of this size it will need to be broken down into smaller parts, I have done some research and here is what I have so far.</p>
  
  <ul>
  <li>Server-side config will be required to accept large POST requests and probably a 64bit machine to handle <a href="https://stackoverflow.com/questions/5053290/large-file-upload-though-html-form-more-than-2-gb">anything over 4Gb</a>.</li>
  <li>AWS supports <a href="http://docs.aws.amazon.com/AmazonS3/latest/dev/mpuoverview.html" rel="noreferrer">multipart upload.</a> </li>
  <li>HTML5 <a href="http://www.html5rocks.com/en/tutorials/file/filesystem/" rel="noreferrer">FileSystemAPI</a> has a persistent uploader that uploads the file in chunks.</li>
  <li>A library for <a href="https://stackoverflow.com/questions/6111517/ruby-bittorrent-library">Bitorrent</a> although this requires a transmission client which is not ideal</li>
  </ul>
  
  <p>Can all of these methods be resumed like FTP, the reason I dont want to use FTP is that I want to keep in the web app if this is possible? I have used carrierwave and paperclip but I am looking for something that will be able to be resumed as uploading a 5Gb file could take some time!</p>
  
  <p>Of these approaches I have listed I would like to undertand what has worked well and if there are other approaches that I may be missing? No plugins if possible, would rather not use Java Applets or Flash. Another concern is that these solutions hold the file in memory while uploading, that is also a constraint I would rather avoid if possible.</p>