System and method for controlling storage of electronic files

Abstract

A storage control system comprising overlap retrieval means for retrieving overlap files, which are stored in at least one storage area of a plurality of storage areas, and which overlap one another, and storage controlling means for storing data of at least one overlapped part of the retrieved overlap files in a storage area having reliability that is greater than that of the storage area in which the data of this overlapped part is stored. A large number of files are stored in a plurality of storage areas, and overlap retrieval means retrieves overlap files from among a number of files, which is smaller than the number of stored files.

1 . A storage control system, comprising: 
 overlap retrieval means for retrieving overlap files, which are stored in at least one storage area of a plurality of storage areas, and which overlap one another; and    storage control means for storing data of at least one overlapped part of said retrieved overlap files in a storage area having reliability greater than that of the storage area in which the data of the overlapped part is stored.    
   
   
       2 . The storage control system according to  claim 1 , wherein a plurality of files are stored in said plurality of storage areas, and said overlap retrieval means retrieves said overlap files from among a number of files, which is less than the number of said stored files.  
   
   
       3 . The storage control system according to  claim 2 , comprising: 
 means for reading a file from at least one storage area; and    file marking means for marking a read file each time a file is read out, and controlling the number of marked files to a number, which is less than the number of said stored files, wherein    said overlap retrieval means retrieves a file, which overlaps a certain file, from among a plurality of files that have been marked.    
   
   
       4 . The storage control system according to  claim 3 , wherein said overlap retrieval means determines, sequentially from the most recently marked file, whether or not a file from among said marked plurality of files overlaps said certain file.  
   
   
       5 . The storage control system according to  claim 3 , wherein, when said overlap file cannot be found among said marked plurality of files, said overlap retrieval means retrieves, from among one or more files for which either the entire or a part of the filename, and/or the file size matches that of said certain file, a file, which overlaps said certain file.  
   
   
       6 . The storage control system according to  claim 1 , further comprising: 
 a reliability storage region capable of storing reliability information related to the reliability of each of a plurality of storage areas, 
 wherein, when two files completely overlap one another, said storage control means determines, based on said reliability information, which file is in a storage area having high reliability, clears the location of the file, which is in a low-reliability storage area, and leaves the file in the high-reliability storage area.  
   
   
   
       7 . The storage control system according to  claim 1 , further comprising: 
 a reliability storage region capable of storing reliability information related to the reliability of each of a plurality of storage areas,    wherein, when pre- and post-update files partially overlap one another, said storage control means, based on said reliability information, stores the post-update file in a storage area that is more reliable than the storage area in which the old file is stored, generates a difference file for the pre- and post-update files, stores said generated difference file in at least one storage area, and clears the location where at least data of the overlapped parts of said old file reside.    
   
   
       8 . The storage control system according to  claim 1 , further comprising: 
 log file updating means for writing information related to said retrieved overlap files to a prescribed log file, wherein said overlap retrieval means retrieves said overlap files based on the information recorded in said log file.    
   
   
       9 . The storage control system according to  claim 1 , wherein said storage control system is connected to a separate storage control system so as to enable communications, and 
 said storage control means, by transferring all the files, which reside in a primary storage area of said plurality of storage areas, to said separate storage control system, copies said all the files to a secondary storage area accessible by said separate storage control system, and thereafter, when a certain file of said primary storage area is updated, transfers at least the file metadata of the post-update file to said separate storage control system.    
   
   
       10 . The storage control system according to  claim 1 , wherein said storage control system connects, so as to enable communications, to a backup device for acquiring a file stored in at least one storage area, and backing up the file in a backup storage area, and 
 hides said retrieved overlap file from said backup device.    
   
   
       11 . The storage control system according to  claim 10 , wherein said storage control means generates a metadata aggregate file in which is recorded a large number of file metadata corresponding to a respective large number of files stored in said plurality of storage areas, stores said generated metadata aggregate file in at least one storage area, and sends said stored metadata aggregate file to said backup device, thereby enabling restoration based on the file metadata recorded in said metadata aggregate file.  
   
   
       12 . The storage control system according to  claim 10 , wherein said storage control means creates a physical address image file of at least one physical address image from said plurality of storage areas, and sends said created physical address image file to said backup device.  
   
   
       13 . The storage control system according to  claim 1 , wherein said storage control means backs up data of at least one overlapped part of said retrieved overlap files in a storage area having reliability greater than that of the storage area in which the data of the overlapped part is stored.  
   
   
       14 . The storage control system according to  claim 12 , wherein, when a backup source file is updated after said backup, said storage control means reflects the results of the update in the backup destination.  
   
   
       15 . The storage control system according to  claim 1 , comprising: 
 a threshold value storage region for storing a threshold value for the number of files, which are overlapped; and    means for prompting a user to delete an unnecessary overlap file when the number of said retrieved overlap files becomes greater than said threshold value.    
   
   
       16 . A storage control system, comprising: 
 overlap retrieval means for retrieving overlap files, which overlap one another, from among a number of files that is less than the number of files stored in a plurality of storage areas; and    controlling means for carrying out prescribed processing for said retrieved overlap files.    
   
   
       17 . A storage control method, comprising the steps of: 
 retrieving overlap files, which are stored in at least one storage area of a plurality of storage areas, and which overlap one another; and    storing data of at least one overlapped part of said retrieved overlap files in a storage area having reliability that is greater than that of the storage area in which the data of the overlapped part is stored.    
   
   
       18 . A storage control method, comprising the steps of: 
 retrieving overlap files, which overlap one another, from among a number of files that is less than the number of files stored in a plurality of storage areas; and    carrying out prescribed processing for said retrieved overlap files.    
   
   
       19 . A recording medium recording a computer program for causing a computer to retrieve overlap files, which are stored in at least one storage area of a plurality of storage areas and which overlap one another, and to store data of at least one overlapped part of said retrieved overlap files in a storage area having reliability that is greater than that of the storage area in which the data of this overlapped part is stored.  
   
   
       20 . A recording medium recording a computer program for causing a computer to retrieve overlap files, which overlap one another, from among a number of files that is less than the number of files stored in a plurality of storage areas, and to carry out prescribed processing for said retrieved overlap files.  
   
   
       21 . A storage control system, comprising: 
 at least one storage region; and    at least one processor,    wherein said at least one processor reads a file from at least one storage device of a plurality of storage devices in which a large number of files are stored, and each time a file is read out, marks the read file on said storage region, and controls the number of marked files to a number, which is less than the number of files stored in said plurality of storage device, retrieves a file, which overlaps a certain file, from among a plurality of files that have been marked, and stores data of at least one overlapped part of said retrieved overlap file in a storage device having reliability that is greater than that of the storage device in which the data of this overlapped part is stored.