title: Mongodb gives "Can't take a write lock > while out of disk space" error with plenty of space
body: <p>I have mongodb running on a linux server with 90% disk usage (as confirmed by df). Every operation is causing the following error:</p>
  
  <blockquote>
    <p>db.dropDatabase() {   "ok" : 0,   "errmsg" : "Can't take a write lock
    while out of disk space",     "code" : 14031 }</p>
  </blockquote>
  
  <p>'df -k' shows:</p>
  
  <pre><code>Filesystem     1K-blocks     Used Available Use% Mounted on
  /dev/xvda1      16380820 14622652   1657920  90% /
  devtmpfs         2015972       56   2015916   1% /dev
  tmpfs            2024984        0   2024984   0% /dev/shm
  </code></pre>
  
  <p>There seems to be plenty of disk space. Is it possible that the database is corrupted? The disk had originally ran out of disk space but then I deleted many files and cleared 10% but the error persists. </p>
  
  <p>Can anyone recommend what next steps to take?</p>
  
  <p>Thanks</p>