title: Issues with s4cmd
body: <p>I have about 50GB data to upload to S3 bucket but s3cmd is unreliable and very slow. the sync doesn't seem to work because of the timeout error.</p>
  
  <p>I switched to <a href="https://github.com/bloomreach/s4cmd" rel="nofollow">s4cmd</a> it works great, multi threaded and fast. </p>
  
  <pre><code>     s4cmd dsync -r -t 1000 --ignore-empty-source forms/ s3://bucket/J/M/
  </code></pre>
  
  <p>The above uploads a set of files and then throws error - 
  <strong>[Thread Failure] Unable to read data from source: /home/ubuntu/path to file</strong>
  The source file contains an image file so there is nothing wrong there.</p>
  
  <p>s4cmd has options like --retry for the command to restart if it fails but this also doesn't seem to work.
   If you have come across a solution to prevent this error, Please share.</p>