title: Remove old commit information from a git repository to save space
body: <p>I have a repository for storing some large binary files (tifs, jpgs, pdfs) that is growing pretty large. There is also a fair amount of files that are created, removed, and renamed and I don't care about the individual commit history. This question is somewhat simplified because I'm dealing with a repository that has no branches and no tags.</p>
  
  <p>I'm curious if there's an easy way to remove some of the history from the system to save space.</p>
  
  <p>I found an old thread <a href="http://git.661346.n2.nabble.com/purging-unwanted-history-td1507638.html">on the git mailing list</a> but it doesn't really specify how to use this (i.e. what the $drop is):</p>
  
  <pre><code>git filter-branch --parent-filter "sed -e 's/-p $drop//'" \
          --tag-name-filter cat -- \
          --all ^$drop 
  </code></pre>