title: Syncing a very out-of-date github repository
body: <p>I have a massive github repository that has fallen badly out of sync. I have about 100 MB of source files (that should be pushed) and ~10 TB of data (that should not be pushed). </p>
  
  <p>I have done </p>
  
  <pre><code>git add .
  git commit -m 'Resync'
  </code></pre>
  
  <p>but then I noticed many files that should not be pushed have been added to the commit. I added these files to my <code>.gitignore</code> file, but now when I do those above lines again, it seems that nothing is added except the new <code>.gitignore</code> file. </p>
  
  <p>I think I am supposed to do </p>
  
  <pre><code>git rm -r --cached .
  </code></pre>
  
  <p>but I am terrified of losing all of my work in the last year. What am I supposed to do? </p>