MySQL error in file: /engine/modules/randimg.php at line 17

Error Number: 1021

The Error returned was:
Disk full (/tmp/#sql-temptable-3b3-19d6d6-3fd91.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")

SQL query:

SELECT id, short_story, title, date, alt_name, category FROM dle_post WHERE approve='1' ORDER BY RAND() LIMIT 1