Database Problem

Error writing file '/tmp/MYyKT9yZ' (Errcode: 28 "No space left on device")
SELECT 9mj_videodata.id, 9mj_videodata.diskid, title, subtitle, language, year, director, plot, imgurl, owner_id, 9mj_users.name AS owner, 9mj_lent.who, md5, comment, disklabel, imdbID, actors, runtime, country, filename, filesize, filedate, audio_codec, video_codec, video_width, video_height, istv, lastupdate, mediatype, custom1, custom2, custom3, custom4, created, !ISNULL(9mj_userseen.video_id) AS seen FROM 9mj_videodata LEFT JOIN 9mj_users ON 9mj_videodata.owner_id = 9mj_users.id LEFT JOIN 9mj_userseen ON 9mj_videodata.id = 9mj_userseen.video_id AND 9mj_userseen.user_id = 1 LEFT JOIN 9mj_lent ON 9mj_videodata.diskid = 9mj_lent.diskid WHERE mediatype != 50 AND ISNULL(9mj_userseen.video_id) AND istv = 0 ORDER BY title, subtitle