The website I have just made live on Magento has crashed after one day of activity.

I have checked the error log and it begins with the following ...

> a:5:{i:0;s:144:"SQLSTATE[HY000]: General error: 126 Incorrect key file
> for table '/tmp/#sql_dda_0.MYI';

 try to repair it, query was: **DESCRIBE `log_visitor_info`";i:1;s:3547:"#0**

Does anyone know what this means, or can assist me in fixing this issue please?
Thanks