SupeSite info: MySQL Query Error

Time: 2010-3-15 8:23pm
Script: /index.php

SQL: SELECT m.* FROM cdb_members m ORDER BY m.posts DESC LIMIT 0,10
Error: Error writing file '/var/tmp/MYMiKEnN' (Errcode: 28)
Errno.: 3

Similar error report has beed dispatched to administrator before.