Storage system having a thin provisioning function

Abstract

Data migration includes copying between normal volumes and thin provisioned volumes. Data in a normal volume can be copied to a thin provisioned volume. Alternatively, data structures can be provided to facilitate converting a normal volume into a thin provisioned volume without actual copying of data. Copying from a thin provisioned volume to a normal volume is also disclosed.

1 . (canceled) 
     
     
         2 . A first storage system coupled to a second storage system, the second storage system managing a second storage device, the first storage system comprising:
 a first storage device; and   a controller configured to manage:
 a storage area configured by a plurality of storage segments, the plurality of storage segments including a first storage segment corresponding to a first storage area of the first storage device and a second storage segment corresponding to a second storage area of the second storage device; and 
 a virtual volume to which at least one of the storage segments is allocated after receiving a write request to the virtual volume. 
   
     
     
         3 . The first storage system according to  claim 2 ,
 wherein a size of the first storage segment is the same as the size of the second storage segment.   
     
     
         4 . The first storage system according to  claim 2 ,
 wherein the first storage segment and the second storage segment are units for allocating to the virtual volume.   
     
     
         5 . The first storage system according to  claim 2 ,
 wherein if the allocated storage segment is the first storage segment, the controller is configured to store data corresponding to the write request into the first storage area.   
     
     
         6 . The first storage system according to  claim 2 ,
 wherein if the allocated storage segment is the second storage segment, the controller is configured to transfer data corresponding to the write request to the second storage system to store the data into the second storage area.   
     
     
         7 . The first storage system according to  claim 2 ,
 wherein the virtual volume has a plurality of virtual storage areas, and   wherein the virtual volume has a plurality of virtual storage areas and the at least one storage segment is allocated to at least one virtual storage area to which the write request is directed.   
     
     
         8 . A first storage system coupled to a second storage system comprising:
 a virtual volume;   a storage area configured by a plurality of storage segments, the plurality of storage segments including a first storage segment corresponding to a first storage area of a first storage device in the first storage system and a second storage segment corresponding to a second storage area of a second storage device managed by the second storage system; and   a controller configured to, after receiving a write request to the virtual volume, allocate at least one of the storage segments to the virtual volume.   
     
     
         9 . The first storage system according to  claim 8 ,
 wherein a size of the first storage segment is the same as the size of the second storage segment.   
     
     
         10 . The first storage system according to  claim 8 ,
 wherein the first storage segment and the second storage segment are units for allocating to the virtual volume.   
     
     
         11 . The first storage system according to  claim 8 ,
 wherein if the allocated storage segment is the first storage segment, the controller is configured to store data corresponding to the write request into the first storage area.   
     
     
         12 . The first storage system according to  claim 8 ,
 wherein if the allocated storage segment is the second storage segment, the controller is configured to transfer data corresponding to the write request to the second storage system to store the data into the second storage area.   
     
     
         13 . The first storage system according to  claim 8 ,
 wherein the virtual volume has a plurality of virtual storage areas, and   wherein the virtual volume has a plurality of virtual storage areas and the at least one storage segment is allocated to at least one virtual storage area to which the write request is directed.   
     
     
         14 . In a first storage system coupled to a second storage system, the second storage system managing a second storage device, the first storage system including a first storage device and a controller, the controller performing a method comprising the steps of:
 configuring a storage area by a plurality of storage segments, the plurality of storage segments including a first storage segment corresponding to a first storage area of the first storage device and a second storage segment corresponding to a second storage area of the second storage device; and   allocating at least one of the storage segments to a virtual volume after receiving a write request to the virtual volume.   
     
     
         15 . The method according to  claim 14 ,
 wherein a size of the first storage segment is the same as the size of the second storage segment.   
     
     
         16 . The method according to  claim 14 ,
 wherein the first storage segment and the second storage segment are units for allocating to the virtual volume.   
     
     
         17 . The method according to  claim 14 , further comprising the step of:
 if the allocated storage segment is the first storage segment, storing data corresponding to the write request into the first storage area.   
     
     
         18 . The method according to  claim 14 , further comprising the step of:
 if the allocated storage segment is the second storage segment, transferring data corresponding to the write request to the second storage system to store the data into the second storage area.   
     
     
         19 . The method according to  claim 14 ,
 wherein the virtual volume has a plurality of virtual storage areas, and   wherein the virtual volume has a plurality of virtual storage areas and the at least one storage segment is allocated to at least one virtual storage area to which the write request is directed.   
     
     
         20 . In a first storage system, coupled to a second storage system, and including a virtual volume; a storage area configured by a plurality of storage segments, the plurality of storage segments including a first storage segment corresponding to a first storage area of a first storage device in the first storage system and a second storage segment corresponding to a second storage area of a second storage device managed by the second storage system; and a controller, a method performed the controller comprising the steps of:
 receiving a write request to the virtual volume, and   allocating at least one of the storage segments to the virtual volume in response to the write request.   
     
     
         21 . The method according to  claim 20 ,
 wherein a size of the first storage segment is the same as the size of the second storage segment.   
     
     
         22 . The method according to  claim 20 ,
 wherein the first storage segment and the second storage segment are units for allocating to the virtual volume.   
     
     
         23 . The method according to  claim 20 , further comprising the step of:
 if the allocated storage segment is the first storage segment, storing data corresponding to the write request into the first storage area.   
     
     
         24 . The method according to  claim 20 , further comprising the step of:
 if the allocated storage segment is the second storage segment, transferring data corresponding to the write request to the second storage system to store the data into the second storage area.   
     
     
         25 . The method according to  claim 20 ,
 wherein the virtual volume has a plurality of virtual storage areas, and   wherein the virtual volume has a plurality of virtual storage areas and the at least one storage segment is allocated to at least one virtual storage area to which the write request is directed.