title: Can't back up SD card with dd, complains "Input/Output Error"
body: <p>I have successfully backed up my SD card twice by issuing the following command</p>
  
  <pre><code>sudo dd if=/dev/sdb of=/home/user/Documents/raspi/images/raspi1.v2.iso bs=1M
  </code></pre>
  
  <p>However, now it is giving me the following error:</p>
  
  <pre><code>dd: reading `/dev/sdb': Input/output error
  3027+1 records in
  3027+1 records out
  3174977536 bytes (3.2 GB) copied, 200.723 s, 15.8 MB/s
  </code></pre>
  
  <p>Looking around the net, this seems to indicate a corrupted SD card. However, my raspi (which I runs off of this SD card) runs fine (ish) and <a href="https://askubuntu.com/questions/69932/is-there-an-sd-card-diagnostic-utility">Disk Utility</a> claims that the sd card is not corrupted. </p>
  
  <p>Is there another way I can find out why <code>dd</code> is complaining, if the card is corrupted, and if so, how to fix the SD card.</p>
  
  <p><strong>UPDATE:</strong></p>
  
  <p>I gave up trying to run <code>dd</code> on the SD card, but I did figure out what was corrupting my SD card, it was the updating of the Raspi firmware as specified on <a href="https://sites.google.com/site/semilleroadt/home/raspberry-pi" rel="nofollow noreferrer">this</a> site</p>