If you use a free blogging service like Blogger.com, you do not have a database of your posts in case of a failure at the site. But you can backup your blog for free at Blogbackupr.com. You just need the URL of your blog and an e-mail to which you want your password sent. If you ever need to restore a post (if you accidentally deleted it, for instance), you can retrieve from blogbackupr.com.