Data copying method and apparatus in a thin provisioned system

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 . A Storage system coupled to a host computer, the storage system comprising: 
 a storage controller coupled to a plurality of physical storage devices, that conducts an write request with logical block address from the host computer;    a source volume configured with at least one of the plurality of physical storage devices for storing write data associated with the write request;    wherein based upon a request from the host computer for migrating data in the source volume to a target volume, the storage controller allocates at least one of storage segments in the plurality of physical storage devices to the target volume and associates the allocated storage segment in the target volume with the logical block address containing the write data to copy the write data from the source volume to the target volume.    
   
   
       2 . A storage system coupled to a host computer, the storage system comprising: 
 a storage controller coupled to a plurality of physical storage devices, that conducts an write request with the logical block address from the host computer;    a source volume configured with a least one of storage segments in the plurality of physical storage devices for storing write data associated with the write request, wherein each of the storage segments is allocated and associated with the logical block address, if the storage segment designated by the logical block address does not exist on the source volume;    wherein based upon a request from the host computer for migrating data in the source volume to a target volume, the storage controller copies data in the source storage volume to a location on the target volume that is identified by the logical block address associated with the storage segment, and fills locations on the target volume with NULL characters which do not correspond to any storage segments in the source volume.