title: What is the difference between journal and non journal Mongodb database
body: <p>i just installed mongodb 32 bit version, this is the message which prints in my terminal when i start mongodb</p>
  
  <pre><code>Server has startup warnings: 
  Wed Jul 16 09:53:43.759 [initandlisten] 
  Wed Jul 16 09:53:43.759 [initandlisten] ** NOTE: This is a 32 bit MongoDB binary. 
  Wed Jul 16 09:53:43.759 [initandlisten] **       32 bit builds are limited to less than 2GB of data (or less with --journal).
  Wed Jul 16 09:53:43.759 [initandlisten] **       Note that journaling defaults to off for 32 bit and is currently off.
  Wed Jul 16 09:53:43.759 [initandlisten] **       See http://dochub.mongodb.org/core/32bit
  Wed Jul 16 09:53:43.759 [initandlisten] 
  &gt;
  </code></pre>
  
  <p>From here i noticed or understood 2 things, my mongodb database is limited to storage of less than 2gb database</p>
  
  <p>it is non journalized,</p>
  
  <p>Journalizing makes the space decrease much further</p>
  
  <p>I was wondering </p>
  
  <ol>
  <li><p>what is this journal/non-journal mongodb database </p></li>
  <li><p>what is the advantage of journal database over nonjournal database or vice versa?</p></li>
  <li><p>Is it necessary to journal my database?</p></li>
  </ol>
  
  <p>Please help me in this</p>
  
  <p>Thanks</p>