Error 28

I have been running my blog for over a year now without any problems. Today if I click on any one of my categories I get this message: WordPress database error: [Got error 28 from storage engine]
SELECT DISTINCT * FROM wp_posts LEFT JOIN wp_post2cat ON (wp_posts.ID = wp_post2cat.post_id) LEFT JOIN wp_categories ON (wp_post2cat.category_id = wp_categories.cat_ID) WHERE 1=1 AND (category_id = ‘3’) AND post_date_gmt <= ‘2006-10-19 10:42:59’ AND (post_status = “publish” OR post_author = 1 AND post_status != ‘draft’ AND post_status != ‘static’) AND post_status != “attachment” GROUP BY wp_posts.ID ORDER BY post_date DESC LIMIT 0, 5

How do I get my blog back??? I cannot lose a years worth of posts.