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 third storage apparatus, coupled to a first storage apparatus which is coupled to an information processing apparatus and is a copy source of both a synchronous remote copy operation to the third storage apparatus and an asynchronous remote copy operation to a second storage apparatus coupled to the first storage apparatus and the third storage apparatus, and
 wherein the first storage apparatus has a first logical volume, and the second storage apparatus has a second logical volume,   the third storage apparatus comprising:
 a plurality of disks configuring a third logical volume including a plurality of data blocks; and 
 a control unit, having a memory storing a first bitmap including a plurality of bits and a second bitmap including a plurality of bits, and executing reception processing of a remote copy request of the synchronous remote copy operation from the first storage apparatus, and update processing of a data block included in the third logical volume according to the remote copy request, 
 wherein both the plurality of bits included in the first bitmap and the plurality of bits included in the second bitmap indicate whether each one of the plurality of data blocks included in the third logical volume is updated or not, 
 wherein, after a first time when the first bitmap is cleared, the control unit sets a bit included in the first bitmap, which corresponds to a data block in the third logical volume targeted by the update processing, as a differential data between the third logical volume and the second logical volume, 
 wherein, after a second time when the second bitmap is cleared, which is different from the first time, the control unit sets a bit included in the second bitmap, which corresponds to a data block in the third logical volume targeted by the update processing, as a differential data between the third logical volume and the second logical volume, and 
 wherein the first and second bitmaps are cleared repeatedly. 
   
   
   
       2 . A third storage apparatus according to  claim 1 , wherein the control unit sends data blocks corresponding to bits, being set in the first bitmap or the second bitmap, to the second storage apparatus, in a case of a failure related to the first storage apparatus. 
   
   
       3 . A third storage apparatus according to  claim 1 , wherein the third storage apparatus is placed in a third site which is different from a first site in which the first storage apparatus is placed and a second site in which the second storage apparatus is placed. 
   
   
       4 . A method for managing updates in a third storage apparatus, coupled to a first storage apparatus which is coupled to an information processing apparatus and is a copy source of both a synchronous remote copy operation to the third storage apparatus and an asynchronous remote copy operation to a second storage apparatus coupled to the first storage apparatus and the third storage apparatus,
 wherein the first storage apparatus has a first logical volume, and the second storage apparatus has a second logical volume, and   wherein the third storage apparatus has a third logical volume including a plurality of data blocks, a first bitmap including a plurality of bits, and a second bitmap including a plurality of bits, both the plurality of bits included in the first bitmap and the plurality of bits included in the second bitmap indicate whether each one of the plurality of data blocks included in the third logical volume is updated or not,   the method comprising the steps of:
 receiving a remote copy request of the synchronous remote copy operation from the first storage apparatus; 
 updating a data block included in the third logical volume according to the remote copy request; 
 after a first time when the first bitmap is cleared, setting a bit included in the first bitmap, which corresponds to a data block in the logical volume targeted by the updating step, as a differential data between the third logical volume and the second logical volume; and 
 after a second time when the second bitmap is cleared, which is different from the first time, setting a bit included in the second bitmap, which corresponds to a data block in the logical volume targeted by the updating step, as a differential data between the third logical volume and the second logical volume, 
 wherein the first and second bitmaps are cleared repeatedly. 
   
   
   
       5 . A method for managing updates according to  claim 4 , further comprising the step of:
 sending data blocks corresponding to bits, being set in the first bitmap or the second bitmap, to the second storage apparatus, in a case of a failure related to the first storage apparatus.   
   
   
       6 . A method for managing updates according to  claim 5 , wherein the third storage apparatus is placed in a third site which is different from a first site in which the first storage apparatus is placed and a second site in which the second storage apparatus is placed. 
   
   
       7 . A remote copy system comprising:
 a first storage apparatus coupled to an information processing apparatus, having a first control unit and a first logical volume including a plurality of data blocks;   a second storage apparatus coupled to the first storage apparatus, having a second control unit and a second logical volume including a plurality of data blocks; and   a third storage apparatus coupled to the first storage apparatus and the second storage apparatus, having a third control unit and a third logical volume including a plurality of data blocks,   wherein the first storage apparatus is a copy source of both a synchronous remote copy operation to the third storage apparatus and an asynchronous remote copy operation to the second storage apparatus,   wherein the third control unit has a memory storing a first bitmap including a plurality of bits and a second bitmap including a plurality of bits, and executing reception processing of a remote copy request of the synchronous remote copy operation from the first storage apparatus, and update processing of a data block included in the third logical volume according to the remote copy request,   wherein both the plurality of bits included in the first bitmap and the plurality of bits included in the second bitmap indicate whether each one of the plurality of data blocks included in the third logical volume is updated or not,   wherein, after a first time when the first bitmap is cleared, the third control unit sets a bit included in the first bitmap, which corresponds to a data block in the third logical volume targeted by the update processing, as a differential data between the third logical volume and the second logical volume,   wherein, after a second time when the second bitmap is cleared, which is different from the first time, the third control unit sets a bit included in the second bitmap, which corresponds to a data block in the third logical volume targeted by the update processing, as a differential data between the third logical volume and the second logical volume, and   wherein the first and second bitmaps are cleared repeatedly.   
   
   
       8 . A remote copy system according to  claim 7 , wherein the third control unit sends data blocks corresponding to bits, being set in the first bitmap or the second bitmap, to the second storage apparatus, in a case of a failure related to the first storage apparatus. 
   
   
       9 . A remote copy system according to  claim 7 , wherein the third storage apparatus is placed in a third site which is different from a first site in which the first storage apparatus is placed and a second site in which the second storage apparatus is placed. 
   
   
       10 . A method for remote copying in a remote copy system including a first storage apparatus coupled to an information processing apparatus, a second storage apparatus coupled to the first storage apparatus, and a third storage apparatus coupled to the first storage apparatus and the second storage apparatus,
 wherein the first storage apparatus is a copy source of both a synchronous remote copy operation to the third storage apparatus and an asynchronous remote copy operation to the second storage apparatus,   wherein the first storage apparatus has a first logical volume including a plurality of data blocks, and the second storage apparatus has a second logical volume including a plurality of data blocks, and   wherein the third storage apparatus has a third logical volume including a plurality of data blocks, a first bitmap including a plurality of bits, and a second bitmap including a plurality of bits, both the plurality of bits included in the first bitmap and the plurality of bits included in the second bitmap indicate whether each one of the plurality of data blocks included in the third logical volume is updated or not,   the method comprising the steps of:   receiving a remote copy request of the synchronous remote copy operation from the first storage apparatus;   updating a data block included in the third logical volume according to the remote copy request;   after a first time when the first bitmap is cleared, setting a bit included in the first bitmap, which is corresponds to a data block in the logical volume targeted by the updating step, as a differential data between the third logical volume and the second logical volume; and   after a second time when the second bitmap is cleared, which is different from the first time, setting a bit included in the second bitmap, which is corresponding a data block in the logical volume targeted by the updating step, as a differential data between the third logical volume and the second logical volume,   wherein the first and second bitmaps are cleared repeatedly.   
   
   
       11 . A method according to  claim 10 , further comprising step of:
 sending step to send data blocks corresponding to bits, being set, in the first bitmap or the second bitmap, to the second storage apparatus, in a case of a failure related to the first storage apparatus.   
   
   
       12 . A method according to  claim 10 , wherein the third storage apparatus is placed in a third site which is different from a first site in which the first storage apparatus is placed and a second site in which the second storage apparatus is placed.