Storage system, method of controlling storage system, and storage device

Abstract

The present invention provides a storage system and a method of controlling the storage system, in which a second site rapidly resumes system process when a first site is damaged. The storage system comprises a first site including a first storage device, a second site including a second storage device, and a third site including a third storage device, and the method of controlling the storage system comprises a step of making a logical volume of the second storage device consistent with a logical volume of the first storage device by remotely copying only the differential data between the logical volume of the first storage device and the logical volume of the second storage device from a logical volume of the third storage device to the logical volume of the second storage device when the first site is damaged.

1 . (canceled)  
   
   
       2 . A storage apparatus comprising: 
 a control unit;    a plurality of disks forming a logical volume; and    a bitmap indicating a location in the logical volume,    wherein the control unit receives an instruction including bitmap clear timing information, based on which the control unit clears the bitmap,    wherein when the control unit receives a write request to the logical volume, the write request including a time stamp, the control unit compare a first time specified by the time stamp and a second time specified by the bitmap clear timing information, and    wherein if the first time is later than the second time, the control unit clears the bitmap.    
   
   
       3 . A storage apparatus according to  claim 2 , wherein after the control unit clears the bitmap, the control unit starts to record information indicating a location, in which data is updated according to the write request, by using the bitmap.  
   
   
       4 . A storage apparatus according to  claim 2 , 
 wherein when the control unit does not receive the write request to the logical volume, the control unit compares a current time and the second time, and    wherein if the current time is later than the second time, the control unit clears the bitmap.    
   
   
       5 . A method for managing location information in a logical volume by a storage system having a control unit, a plurality of disks configuring the logical volume, and a bitmap used for recording the location information, comprising the steps of: 
 receiving an instruction including bitmap clear timing information, based on which the control unit clears the bitmap;    receiving a write request to the logical volume, the write request including a time stamp;    comparing a first time specified by the time stamp and a second time specified by the bitmap clear timing information; and    clearing the bitmap, if the first time is later than the second time.    
   
   
       6 . A method for managing location information according to  claim 5 , further comprising a step of; 
 starting to record information indicating a location, in which data is updated according to the write request, by using the bitmap.    
   
   
       7 . A method for managing location information according to  claim 5 , further comprising steps of; 
 comparing a current time and the second time, if the control unit does not receive the write request to the logical volume; and    clearing the bitmap, if the current time is later than the second time.    
   
   
       8 . A third storage apparatus comprising; 
 a third control unit;    a plurality of disks configuring a third logical volume; and    a plurality of tables used for recording location information in the third logical volume,    wherein the third control unit receives a write request from a first storage apparatus coupled to the third storage apparatus, and records the location information indicating a location, in which data is to be stored according to the write request, by using the plurality of tables, and    wherein the third control unit clears one of the plurality of tables in relation to a copy operation between the first storage apparatus and a second storage apparatus coupled to the first storage apparatus.    
   
   
       9 . A third storage apparatus according to  claim 8 , wherein the third control unit receives the write request from the first storage apparatus according to a synchronous remote copy operation.  
   
   
       10 . A third storage apparatus according to  claim 8 , wherein the third control unit clears the one of the plurality of tables in relation to an asynchronous remote copy operation between the first storage apparatus and the second storage apparatus.  
   
   
       11 . A method for managing location information in a third logical volume by a third storage apparatus in relation to a copy operation between a first storage apparatus and a second storage apparatus, 
 wherein the third storage system having a third control unit, a plurality of third disks configuring the third logical volume, and a plurality of tables used for recording the location information, comprising the steps of:    receiving a write request from the first storage apparatus;    recording the location information indicating a location, in which data is stored according to the write request, by using the plurality of tables; and    clearing one of the plurality of tables in relation to a copy operation between the first storage apparatus and a second storage apparatus coupled to the first storage apparatus.    
   
   
       12 . A method for managing location information according to  claim 11 , wherein the third control unit receives the write request from the first storage apparatus according to a synchronous remote copy operation.  
   
   
       13 . A method for managing location information according to  claim 11 , wherein the third control unit clears the one of the plurality of tables in relation to an asynchronous remote copy operation between the first storage apparatus and the second storage apparatus.