cache_total_size
                                                    Maximum size of the disk cache.
| 
                                                                     Value  | 
                                                                
                                                                     Integer: 0–INT_MAX.  | 
                                                            
| 
                                                                     Default  | 
                                                                
                                                                     500 (MB)  | 
                                                            
| 
                                                                     How to set  | 
                                                                
                                                                     
                                                                          | 
                                                            
| 
                                                                     Usage  | 
                                                                
                                                                     Seldom used.  |