Disk array system

Abstract

Provided is a disk array system which is connected to a computer and which data is transmitted by the computer, including: a plurality of disk drives for storing user data transmitted by the computer; a cache memory for temporarily storing data sent/received among the computer and the plurality of disk drives; and a control unit for controlling input/output of the data to/from the cache memory, in which the control unit stores user data identification information that is capable of judging whether the user data is stored in a sector of the disk drive. The disk array system according to this invention allows the identification of user data of a disk drive.

1 . A disk array system which is connected to a computer and which is transmitted data by the computer, comprising: 
 a plurality of disk drives for storing user data transmitted by the computer;    a cache memory for temporarily storing data transmitted among the computer and the plurality of disk drives; and    a control unit for controlling input/output of the data to/from the cache memory,    wherein the control unit stores user data identification information that is capable of judging whether the user data is stored in a sector of the disk drive.    
   
   
       2 . The disk array system according to  claim 1 , wherein upon access to the disk drive not in response to a request from the computer, the control unit references the user data identification information to judge whether or not the user data is stored in a sector corresponding to the user data identification information.  
   
   
       3 . The disk array system according to  claim 1 , wherein upon access to the continuous sector located in the disk drive, the control unit references the user data identification information of a subsequent sector to judge whether the user data is stored in the subsequent sector.  
   
   
       4 . The disk array system according to  claim 1 , wherein the control unit stores a guarantee code that is capable of judging whether the user data is correct data, and further stores the user data identification information in addition to the guarantee code to the disk drives.  
   
   
       5 . The disk array system according to  claim 1 , wherein the control unit stores redundant data created from the user data in the disk drive, creates user data identification information that is capable of judging whether the user data is stored in at least a part of a sector corresponding to the redundant data, and stores the created user data identification information corresponding to the redundant data.  
   
   
       6 . The disk array system according to  claim 5 , wherein the control unit stores the created user data identification information in a sector that stores the redundant data.  
   
   
       7 . The disk array system according to  claim 5 , wherein the control unit stores the created user data identification information in the cache memory in a bitmap format.  
   
   
       8 . The disk array system according to  claim 5 , wherein the control unit sets the user data identification information indicating that the user data is not stored in each sector of the disk drive when a RAID area is structured by use of a plurality of storage areas of the disk drive, and further sets the user data identification information indicating that the user data is stored in the sector when the user data is transmitted to the sector of the disk drive.  
   
   
       9 . The disk array system according to  claim 5 , wherein upon restoring data that was stored in the disk drive by use of the redundant data, the control unit references the user data identification information to restore only data of the sector storing the user data.  
   
   
       10 . The disk array system according to  claim 1 , further comprising: 
 a first logical unit; and    a second logical unit,    wherein upon copying data stored in the first logical unit to the second logical unit, the control unit references the user data identification information to copy only data of the sector storing the user data to the second logical unit.    
   
   
       11 . The disk array system according to  claim 1 , further comprising: 
 a first logical unit; and    a second logical unit,    wherein the control unit references the user data identification information to:    when the user data is not stored in a sector of any one of the first logical unit and the second logical unit, integrate the first logical unit and the second logical unit; and    when the user data is stored in a sector of the first logical unit or the second logical unit, notify to that effect.    
   
   
       12 . The disk array system according to  claim 1 , wherein upon copying data stored in the disk array system to another disk array system, the control unit references the user data identification information to copy only data of the sector storing the user data to the another disk array system.  
   
   
       13 . The disk array system according to  claim 1 , wherein upon checking data that was stored in the disk drive, the control unit references the user data identification information to check only data of the sector storing the user data.