Best, Easy and Free Ways to Back up Your Blogger Blog

After writing on my blog for a month, I realized that there is a possibility of losing data online and the need for back ups.  After doing my research, I have found 2 easy ways to back up my blog:
  1. Use Blogger Send to send email every publish post
  2. Use the Export Blog under Blog tools
  3. Sign up for free at
By using disqus, I do not need to back up my comments.  Or do I?