Computer system, data migration monitoring method and data migration monitoring program

A computer control method for controlling migration in a computer system comprising a storage system, a computer for storing data in the storage system, and a management computer, the storage system including a plurality of storage media constituting a plurality of storage areas, and a controller connected to the storage media, the management computer including an interface connected to a network, and a processor connected to the interface, comprising the steps of:

• making by the controller a first logical storage area and a second logical storage area correspond to at least one first storage medium and at least one second storage medium respectively in the plurality of storage media;
• allocating by the controller data storage areas to the first and second logical storage areas from the first and second storage media respectively in accordance with a write request from the computer;
• setting by the controller the allocated second logical storage area as an area to which data to be written from the computer into the first logical storage area are migrated;
• setting by the controller a pairing relation for migrating data from the first logical storage area to the second logical storage area;
• starting by the controller the data migration from the first logical storage area to the second logical storage area;
• making by the controller of the storage system third and fourth logical storage areas correspond to the first and second storage media respectively;
• allocating by the controller data storage areas to the third and fourth logical storage areas from the first and second storage media respectively in accordance with a write request from the computer;
• starting by the controller the allocated fourth logical storage area as an area to which data to be written from the computer into the third logical storage area are migrated;
• starting by the controller a pairing relation for data migration from the third logical storage area to the fourth logical storage area;
• starting by the controller the data migration from the third logical storage area to the fourth logical storage area and the data migration from the first logical storage area to the second logical storage area simultaneously;
• monitoring by the processor the capacity of the data storage area allocated to the first logical storage area and the capacity of the second storage medium to be allocated to the data storage area of the second logical storage area through the network during a period after the setting of the pairing relation for the data migration before the start of the data migration;
• judging by the processor whether an area for storing data stored in the first logical storage area can be covered by the second logical storage area or not;
• and
• outputting, by the processor to an output portion connected to the processor, a result that the data migration fails if the area for storing data stored in the first logical storage area cannot be covered by the second logical storage area;
• performing by the processor of the management computer the monitoring, the judgment and the outputting during the data migration in the pairing relation for the data migration;
• monitoring by the processor of the management computer the capacity of the data storage area allocated to the third logical storage area and the capacity of the second storage medium to be allocated to the data storage area of the fourth logical storage area during the data migration in the pairing relation for the data migration;
• judging by the processor whether an area for storing data stored in the third logical storage area can be covered by the fourth logical storage area or not;
• and
• outputting, by the processor to the output portion, a result that the data migration from the first logical storage area to the second logical storage area or the data migration from the third logical storage area to the fourth logical storage area fails if the area for storing data stored in the first logical storage area cannot be covered by the second logical storage area or if the area for storing data stored in the third logical storage area cannot be covered by the fourth logical storage area.