A Problem has been Encountered

DB Error: Out of resources when opening file '/web/tmp/#sql_409b_28.MYI' (Errcode: 24)
SQL: SELECT g.*, g.type content_type, i.*, s.active, s.secid, s.siteid FROM cms_gal_sites s, cms_gals g, cms_gals_info i WHERE s.galid=g.galid AND g.galid=i.galid AND g.type='video' AND s.siteid='25' AND s.active>0 AND s.active <= UNIX_TIMESTAMP('2017-03-27 15:56:33') AND (s.until >= UNIX_TIMESTAMP('2017-03-27 15:56:33') OR s.until=0) GROUP BY g.galid ORDER BY s.active DESC LIMIT 0,6