Data storage apparatus

Abstract

A method for controlling a storage apparatus connectable to a server, the storage apparatus including a first storage area and a second storage area for storing data, the method comprises: copying the data stored in the first storage area into the second storage area; copying data stored in the location of the first storage area addressed by the command to be accessed by the server into the location of the second storage area before execution of the command when the storage apparatus receives a command for accessing data stored in a location of either of the first storage area and second storage area from the server; and executing the command for accessing at least one of the location in the first storage area and the corresponding location in the second storage area.

1 . A method for controlling a storage apparatus connectable to a server, the storage apparatus including a first storage area and a second storage area for storing data, the method comprising:
 copying data stored in the first storage area into the second storage area;   copying data stored in the location of the first storage area addressed by the command to be accessed by the server into the location of the second storage area before execution of the command when the storage apparatus receives a command for accessing data stored in a location of either of the first storage area and second storage area from the server; and   executing the command for accessing at least one of the location in the first storage area and the corresponding location in the second storage area.   
   
   
       2 . The method according to  claim 1 , wherein the command includes accessing data stored in a location that the copying data stored in the location is unexecuted, the copying copies data stored in the location of the first storage area addressed by the command before the initiation of the execution of the command. 
   
   
       3 . The method according to  claim 1 , wherein an area to be subjected to the copying is divided into predetermined areas, and bitmap information recording whether each of the predetermined areas has undergone the copying is controlled by the storage apparatus, and whether the command is made to an area that has undergone the copying is determined on the basis of the bitmap information. 
   
   
       4 . A storage apparatus connectable to a server, the storage apparatus comprising:
 a data storage module including a first and a second data storage areas for storing data; and   a controller for executing a process including:
 copying the data stored in the first storage area into the second storage area; 
 copying data stored in the location of the first storage area addressed by the command to be accessed by the server into the location of the second storage area before execution of the command when the storage apparatus receives a command for accessing data stored in a location of either of the first storage area and second storage area from the server; and 
 executing the command for accessing at least one of the location in the first storage area and the corresponding location in the second storage area. 
   
   
   
       5 . The storage apparatus according to  claim 4 , wherein the command includes accessing data stored in a location that the copying data stored in the location is unexecuted, the controller further executes copying data stored in the location of the first storage area addressed by the command before the initiation of the execution of the command. 
   
   
       6 . The method according to  claim 4 , wherein an area to be subjected to the copying is divided into predetermined areas, and bitmap information recording whether each of the predetermined areas has undergone the copying is controlled by the storage apparatus, and whether the command is made to an area that has undergone the copying is determined on the basis of the bitmap information. 
   
   
       7 . A storage system comprising:
 a server including a transmitting module for transmitting a command for accessing data; and   a storage apparatus connected to the server, including:
 a data storage module including a first and a second data storage areas for storing data; and 
 a controller for executing a process including: 
   copying the data stored in the first storage area into the second storage area;   copying data stored in the location of the first storage area addressed by the command to be accessed by the server into the location of the second storage area before execution of the command when the storage apparatus receives a command for accessing data stored in a location of either of the first storage area and second storage area from the server; and   executing the command for accessing at least one of the location in the first storage area and the corresponding location in the second storage area.