Error message

• Warning: Cannot modify header information - headers already sent by (output started at /export/web/virtual/studentaffairs_unt_edu/includes/bootstrap.inc:1627) in drupal_send_headers() (line 1486 of /export/web/virtual/studentaffairs_unt_edu/includes/bootstrap.inc).
• PDOException: SQLSTATE[HY000]: General error: 3 Error writing file '/tmp/MLKX3vOb' (Errcode: 28): DELETE FROM {cache_bootstrap} WHERE (cid = :db_condition_placeholder_0) ; Array ( [:db_condition_placeholder_0] => variables ) in cache_clear_all() (line 173 of /export/web/virtual/studentaffairs_unt_edu/includes/cache.inc).