数据库出问题了，这是什么原因，是临时目录不能读写吗，还是数据太多了

141007 22:45:46 [ERROR] /usr/local/mysql/bin/mysqld: Sort aborted: Can't create/write to file '/tmp/MYiPRZOb' (Errcode: 28)
141007 22:47:20 [ERROR] /usr/local/mysql/bin/mysqld: Sort aborted: Can't create/write to file '/tmp/MY8k88pB' (Errcode: 28)
141007 22:48:21 [ERROR] /usr/local/mysql/bin/mysqld: Sort aborted: Can't create/write to file '/tmp/MYlW5EZZ' (Errcode: 28)
141007 22:48:26 [ERROR] /usr/local/mysql/bin/mysqld: Sort aborted: Can't create/write to file '/tmp/MYQ07egA' (Errcode: 28)
141007 22:56:24 [ERROR] /usr/local/mysql/bin/mysqld: Sort aborted: Can't create/write to file '/tmp/MYhgvkiF' (Errcode: 28)
141007 23:06:35 [ERROR] /usr/local/mysql/bin/mysqld: Sort aborted: Can't create/write to file '/tmp/MY5YyUiv' (Errcode: 28)
141007 23:15:10 [ERROR] /usr/local/mysql/bin/mysqld: Sort aborted: Can't create/write to file '/tmp/MYy1xPdc' (Errcode: 28)
141007 23:16:33 [ERROR] /usr/local/mysql/bin/mysqld: Sort aborted: Can't create/write to file '/tmp/MY5KQPN7' (Errcode: 28)
141007 23:23:28 [ERROR] /usr/local/mysql/bin/mysqld: Sort aborted: Can't create/write to file '/tmp/MY4zdi77' (Errcode: 28)
141007 23:25:18 [ERROR] /usr/local/mysql/bin/mysqld: Sort aborted: Can't create/write to file '/tmp/MYgAnaHo' (Errcode: 28)
141007 23:31:24 [ERROR] /usr/local/mysql/bin/mysqld: Sort aborted: Can't create/write to file '/tmp/MYj5URcP' (Errcode: 28)
141007 23:31:38 [ERROR] /usr/local/mysql/bin/mysqld: Sort aborted: Can't create/write to file '/tmp/MYoiCmMO' (Errcode: 28)
141007 23:31:55 [ERROR] /usr/local/mysql/bin/mysqld: Sort aborted: Can't create/write to file '/tmp/MYPaGCwr' (Errcode: 28)
141007 23:39:21 [ERROR] /usr/local/mysql/bin/mysqld: Sort aborted: Can't create/write to file '/tmp/MYuJdY5l' (Errcode: 28)
141007 23:45:02 [ERROR] /usr/local/mysql/bin/mysqld: Sort aborted: Can't create/write to file '/tmp/MY39zMOs' (Errcode: 28)
141007 23:50:25 [ERROR] /usr/local/mysql/bin/mysqld: Sort aborted: Can't create/write to file '/tmp/MYRFW39b' (Errcode: 28)
141007 23:52:24 [ERROR] /usr/local/mysql/bin/mysqld: Sort aborted: Can't create/write to file '/tmp/MYCxRXGr' (Errcode: 28)
141007 23:53:20 [ERROR] /usr/local/mysql/bin/mysqld: Sort aborted: Can't create/write to file '/tmp/MYdhwvvP' (Errcode: 28)
141008  0:04:23 [ERROR] /usr/local/mysql/bin/mysqld: Sort aborted: Can't create/write to file '/tmp/MY42EgNV' (Errcode: 28)
141008  0:07:15 [ERROR] /usr/local/mysql/bin/mysqld: Sort aborted: Can't create/write to file '/tmp/MYhu41KG' (Errcode: 28)
141008  0:12:16 [ERROR] /usr/local/mysql/bin/mysqld: Sort aborted: Can't create/write to file '/tmp/MYqOyKx4' (Errcode: 28)
141008  0:24:43 [ERROR] /usr/local/mysql/bin/mysqld: Sort aborted: Can't create/write to file '/tmp/MYz4Q3Vp' (Errcode: 28)
141008  0:31:12 [ERROR] /usr/local/mysql/bin/mysqld: Sort aborted: Can't create/write to file '/tmp/MYqKR1xP' (Errcode: 28)
141008  0:49:21 [ERROR] /usr/local/mysql/bin/mysqld: Sort aborted: Can't create/write to file '/tmp/MYuS4PaO' (Errcode: 28)
141008  0:55:49 [ERROR] /usr/local/mysql/bin/mysqld: Sort aborted: Can't create/write to file '/tmp/MYl45k6q' (Errcode: 28)
141008  1:08:28 [ERROR] /usr/local/mysql/bin/mysqld: Sort aborted: Can't create/write to file '/tmp/MYkKtuor' (Errcode: 28)
141008  1:10:25 [ERROR] /usr/local/mysql/bin/mysqld: Sort aborted: Can't create/write to file '/tmp/MYxkfsUX' (Errcode: 28)
141008  1:11:15 [ERROR] /usr/local/mysql/bin/mysqld: Sort aborted: Can't create/write to file '/tmp/MYzymJkY' (Errcode: 28)
141008  1:21:04 [ERROR] /usr/local/mysql/bin/mysqld: Sort aborted: Can't create/write to file '/tmp/MYiH2eIf' (Errcode: 28)
141008  1:21:53 [ERROR] /usr/local/mysql/bin/mysqld: Sort aborted: Can't create/write to file '/tmp/MYRhQtuq' (Errcode: 28)