Storage system, data migration method and management computer

A data migration method in a computer system, the computer system comprising a first storage system coupled to a computer, a second storage system coupled to the first storage system, and

• a management computer coupled to the first storage system and the second storage system, wherein the first storage system comprises a plurality of first volumes, a first control unit, and a first data encryption module, wherein the second storage system comprises a plurality of second volumes, a second control unit, and a second data encryption module, and wherein the management computer comprises a memory, the data migration method comprising:
• storing data accessed by the computer in the plurality of first volumes;
• controlling, by the first control unit, the plurality of first volumes based on access from the computer;
• encrypting or decrypting, by the first data encryption module, data stored on one of the plurality of first volumes based on a first encryption method;
• storing data accessed by the computer in the plurality of second volumes;
• controlling, by the second control unit, the plurality of second volumes based on access from the computer;
• encrypting or decrypting, by the second data encryption module, data stored on one of the plurality of second volumes based on a second encryption method;
• storing encryption method compatibility information which indicates compatibility between a plurality of encryption methods including the first encryption method and the second encryption method in the memory of the management computer;
• when the management computer receives a migration instruction of data migration of encrypted data stored in one of the plurality of first volumes, searching, by the management computer, the encryption method compatibility information for an encryption method which has compatibility with the first encryption method used in the first data encryption module included in the first storage system;
• and
• when the second encryption method which is used in the second data encryption module included in the second storage system is compatible with the first encryption method, selecting, by the management computer, the second storage system as a destination of the data migration, and instructing, by the management computer, to migrate the encrypted data stored in the one of the plurality of first volumes, for which the migration instruction was received, to one of the plurality of second volumes.

A management computer coupled to a first storage system and a second storage system, the first storage system having a first volume and a first data encryption module which encrypts or decrypts data stored on the first volume based on a first encryption method, and the second storage system having a second volume and a second data encryption module which encrypts or decrypts data stored on the second volume based on a second encryption method, wherein the management computer comprises:

• a memory that stores encryption method compatibility information which indicates compatibility between a plurality of encryption methods including the first encryption method and the second encryption method;
• a judgment means for determining the compatibility between the first encryption method, which corresponds to the first volume of the first storage system, and the second encryption method, which corresponds to the second volume of the second storage system,
• wherein when the management computer receives a migration instruction of data migration of encrypted data stored in the first volume, the management computer searches the encryption method compatibility information for an encryption method which has compatibility with the first encryption method used in the first data encryption module included in the first storage system, and
• wherein when the second encryption method which is used in the second storage system is compatible with the first encryption method, the management computer selects the second storage system as a destination of the data migration, and instructs to migrate the encrypted data stored in the first volume, for which the migration instruction was received, to the second volume.