title: Magento cache_dir is not writable and throws an error
body: <p>I am new to Mangento. Any operation i do like navigation in the admin panel i am getting the following error.</p>
  
  <p>Can someone tell me where can i find the cache_dir directory in a Magento Installation ?
  Also it was working perfectly fine until 3 days. what could have made this error ?</p>
  
  <p><a href="http://pastebin.com/jHcD82wv" rel="nofollow">http://pastebin.com/jHcD82wv</a></p>