System and method for chunk based tiered storage volume migration

Abstract

System and method for reducing costs of moving data between two or more of multi-tiered storage devices. Specifically, the system operates by moving only high tier portion of data and merely remapping the low tier data to migration target device, which eliminates a large amount of data movement (low tier) while maintaining the SLA of high tier data. Specifically, when a command to migrate a thin provisioned volume is received from a source primary storage device to another target primary storage device, the system doesn't copy all of the tier1 and tier2 chunk data that the source thin provisioned volume holds, but copies only tier1 chunk data to the target storage device. The copy operation is performed after the storage system prepared the target thin provisioned volume on the target side. After that, tier2 chunks are remapped from the primary storage device to another target primary storage device without copying.

1 . A system comprising:
 a first storage system configured to:
 manage a volume, a first type of tier storage area and a second type of tier storage area, 
 allocate a storage area of the first type of tier storage area and the second type of tier storage area to a first logical area of a plurality of logical areas of the volume, if the first storage system receives a first write data from a computer to the volume; 
   and a second storage system configured to:
 manage the volume, another first type of tier storage area and another second type of tier storage area; 
   wherein the volume is configured to be migrated from the first storage system to the second storage system in a status of:
 (i) an allocation of the another first type of tier storage area to the first logical area of the volume, if the first type of tier storage area is allocated to the first logical area of the volume, and 
 (ii) an allocation of the another second type of tier storage area to the first logical area of the volume, if the second type of tier storage area is allocated to the first logical area of the volume. 
   
     
     
         2 . The system according to  claim 1 , wherein the second storage system is further configured to:
 allocate a storage area of the another first type of tier storage area and the another second type of tier storage area to a second logical area of the plurality of logical areas of the volume, if the second storage system receives a second write data from the computer to the volume after the migration.   
     
     
         3 . The system according to  claim 1 , wherein the first storage system and the second storage system are further configured to manage a type of tier storage area attribute for the first logical area of the volume. 
     
     
         4 . The system according to  claim 3 , wherein the first storage system and the second storage system are further configured to manage a type of tier storage area attribute for each of the plurality of logical areas of the volume. 
     
     
         5 . The system according to  claim 1 , wherein the volume is a thin provisioned volume. 
     
     
         6 . The system according to  claim 1 , wherein the type of tier storage area is defined based on at least a type of disk interface. 
     
     
         7 . The system according to  claim 1  wherein the type of tier storage area is defined based on whether the logical area corresponds to another volume of an external storage system. 
     
     
         8 . A storage system, comprising:
 a central processing unit (CPU) that is configured to:   manage a volume, a first type of tier storage area and a second type of tier storage area; and   process a migration of the volume to the storage system in a status of:
 (i) an allocation of the first type of tier storage area to a first logical area of the volume, if a first type of tier storage area of another storage system is allocated to the first logical area of the volume, and 
 (ii) an allocation of the second type of tier storage area to the first logical area of the volume, if a second type of tier storage area of the another storage system is allocated to the first logical area of the volume. 
   
     
     
         9 . The system according to  claim 8 , wherein the CPU is further configured to:
 allocate a storage area of the first type of tier storage area and the second type of tier storage area to a second logical area of the volume, if a second write data from the computer to the volume is received after the migration.   
     
     
         10 . The storage system according to  claim 8 , wherein the CPU is further configured to manage a type of tier storage area attribute for the first logical area of the volume. 
     
     
         11 . The storage system according to  claim 10 , wherein the CPU is further configured to manage a type of tier storage area attribute for each of a plurality of logical areas of the volume. 
     
     
         12 . The storage system according to  claim 8 , wherein the volume is a thin provisioned volume. 
     
     
         13 . The storage system according to  claim 8 , wherein the type of tier storage area is defined based on at least a type of disk interface. 
     
     
         14 . The storage system according to  claim 8 , wherein the type of tier storage area is defined based on whether the logical area corresponds to another volume of an external storage system. 
     
     
         15 . A non-transitory computer readable medium storing instructions for executing a process for a storage system, the instructions comprising:
 managing a volume, a first type of tier storage area and a second type of tier storage area;   processing a migration of the volume to the storage system in a status of:
 (i) an allocation of the first type of tier storage area to a first logical area of the volume, if a first type of tier storage area of another storage system is allocated to the first logical area of the volume, and 
 (ii) an allocation of the second type of tier storage area to the first logical area of the volume, if a second type of tier storage area of the another storage system is allocated to the first logical area of the volume. 
   
     
     
         16 . The non-transitory computer readable medium according to  claim 15 , wherein the instructions further comprise:
 allocating a storage area of the first type of tier storage area and the second type of tier storage area to a second logical area of the volume, if a second write data from the computer to the volume is received after the migration.   
     
     
         17 . The non-transitory computer readable medium according to  claim 15 , wherein the instructions further comprise:
 managing a type of tier storage area attribute for each of a plurality of logical areas of the volume.   
     
     
         18 . The non-transitory computer readable medium according to  claim 15 , wherein the volume is a thin provisioned volume. 
     
     
         19 . The non-transitory computer readable medium according to  claim 15 , wherein the type of tier storage area is defined based on at least a type of disk interface. 
     
     
         20 . The non-transitory computer readable medium according to  claim 15 , wherein the type of tier storage area is defined based on whether the logical area corresponds to another volume of an external storage system.