MYSQL ERROR: Can't create/write to file '/var/tmp/#sql_7f7_0.MAI' (Errcode: 28)

Query: SELECT *, COUNT(*) AS count, SUM(cart_qty) AS qty FROM ms_cart WHERE cart_photo_prod>'0' AND cart_session='1022319120250704055254' AND cart_client='' AND cart_photo_prod_connect!='0' AND cart_order='0' GROUP BY cart_photo_prod_connect, cart_dis_on