Today I had some message in Google webmaster forum about Possible Outages. While crawling your site, we have noticed an increase in the number of transient soft 404 errors around 2012-10-01 02:00 UTC (London, Dublin, Edinburgh). Your site may have experienced outages. I want to know what is possible outage and how to solve it.
Finally i have find out the answer 404 is the default when a page is gone when an attempt is made to access it, and is what will normally be returned. To have a 410 returned by the server when a page is removed, a simple entry in .htaccess will return that specific error code. The format is: Redirect gone removedfile.html Or Redirect gone /removedfile/ Or Redirect gone /directory/removedfile.html For more information, About Soft 404 errors