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 . A remote copy system comprising: 
 a first storage apparatus including a first control unit and at least one disk forming a first logical volume;    a second storage apparatus including a second control unit and at least one disk forming a second logical volume; and    a third storage apparatus including a third control unit and at least one disk forming a third logical volume,    wherein a synchronous remote copy pair is configured by the first logical volume and the third logical volume to store data, received by the third storage apparatus via a synchronous remote copy operation, in the third logical volume, and    wherein an asynchronous remote copy pair is configured by the first logical volume and the second logical volume to store data, received by the second storage apparatus via an asynchronous remote copy operation, in the second logical volume.    
   
   
       2 . A remote copy system according to  claim 1 , 
 wherein the third storage apparatus further includes a plurality of tables,    wherein the third storage apparatus records location information indicating locations in the third logical volume by using the plurality of tables.    
   
   
       3 . A remote copy system according to  claim 2 , 
 wherein the third storage apparatus clears one of the plurality of tables in relation to the asynchronous remote copy operation between the first storage apparatus and the second storage apparatus.    
   
   
       4 . A method for remote copying in a system, 
 wherein the system includes;    a first storage apparatus including a first control unit and at least one disk forming a first logical volume;    a second storage apparatus including a second control unit and at least one disk forming a second logical volume; and    a third storage apparatus including a third control unit and at least one disk forming a third logical volume,    the method comprising the steps of:    configuring a synchronous remote copy pair between the first logical volume and the third logical volume to store data, transmitted from the first storage apparatus to the third storage apparatus via a synchronous remote copy operation, in the third logical volume; and    configuring an asynchronous remote copy pair between the first logical volume and the second logical volume to store data, transmitted from the first storage apparatus to the second storage apparatus via an asynchronous remote copy operation, in the second logical volume.    
   
   
       5 . A method according to  claim 4 , wherein the third storage apparatus further includes a plurality of tables, and the method further comprising the step of: 
 by the third storage apparatus, recording location information indicating locations in the third logical volume by using the plurality of tables.    
   
   
       6 . A method according to  claim 5 , further comprising a step of 
 by the third storage apparatus, clearing one of the plurality of tables in relation to the asynchronous remote copy operation between the first storage apparatus and the second storage apparatus.