Data migration method and computer system

A computer system comprising:

• a virtual managing unit configured to provide a virtual resource;
• and
• a migration manager, wherein
• the migration manager is configured to
• transmit an instruction to associate a second logical volume with a second virtual storage, which is a migration destination of a first virtual storage that provides a first logical volume, the first virtual storage being a virtual storage to which a virtual resource provided by a virtual managing unit is allocated;
• transmit a copy instruction, which is an instruction to copy data from either one of the first logical volume and a copy source logical volume of the first logical volume to the second logical volume, and
• transmit, when copy completion, which is completion of the data copy to the second logical volume, is detected, an erasing instruction, which is an instruction to erase the first virtual storage, to the virtual managing unit, and
• the virtual managing unit erases the first virtual storage in response to the erasing instruction.

A computer-readable recording medium having recorded therein a computer program for causing a computer to execute:

• transmitting an instruction to associate a second logical volume with a second virtual storage, which is a migration destination of a first virtual storage that provides a first logical volume, the first virtual storage being a virtual storage to which a virtual resource provided by a virtual managing unit is allocated;
• transmitting a copy instruction, which is an instruction to copy data from either one of the first logical volume and a copy source logical volume of the first logical volume to the second logical volume;
• and
• transmitting, when copy completion, which is completion of the data copy to the second logical volume, is detected, an erasing instruction, which is an instruction to erase the first virtual storage, to the virtual managing unit.