An Error Was Encountered

Error Number: 1

Can't create/write to file '/tmp/#sql_379e_0.MYI' (Errcode: 28)

SELECT c.content_id, p.page_path, p.page_root, p.page_id, g.ordering, c.content_title, c.content_intro, c.content_body, c.intro_image, c.content_alias, c.topic_id FROM content as c LEFT JOIN content_group as g ON c.content_id=g.content_id JOIN pages as p ON c.topic_id=p.page_id WHERE c.content_id IN (20,19,56,51) ORDER BY g.ordering asc LIMIT 6