Patent ID: 8407702

Claim:
A computer system comprising a plurality of real machines, wherein: the real machines comprise a first real machine and a second real machine which are linked via a network to each other; each of the real machines includes definition information for managing a relationship among virtual machines executed on the real machines, including an identifier of a virtual network interface card (NIC) assigned to the virtual machine and an identifier of a virtual host bus adaptor (HBA) assigned to the virtual machine; the first real machine is a migration source to migrate a virtual machine being executed on the first real machine to the second real machine, and comprises a first virtualizer and a first virtual machine executed by the first virtualizer; the second real machine is a migration destination to which a virtual machine being executed on the first real machine is migrated from the first real machine, and comprises a second virtualizer; at reception of a migration request of the first virtual machine, the second virtualizer receives a first unique information of the first virtual machine, generates a second virtual machine executed by the second virtualizer based on the definition information of the second virtual machine, which includes an identifier of a second virtual NIC assigned to the second virtual machine, an identifier of a second virtual HBA assigned to the second virtual machine, and the received first unique information, in the definition information of the second virtual machine, changes the identifier of the second virtual NIC to an identifier of a first virtual NIC assigned to the first virtual machine and changes the identifier of the second virtual HBA to an identifier of a first virtual HBA assigned to the first virtual machine receives a first state of the first virtual machine, and sets the second virtual machine based on the first state of the first virtual machine and the changed definition information, validates the set second virtual machine, and transmits the previous definition information of the second virtual machine, which is the definition information of the second virtual machine before the change of the definition information of the second virtual machine, to the first virtualizer, and the first virtualizer changes the identifier of the first virtual NIC, which is reserved, to the identifier of the second virtual NIC and changes the identifier of the first virtual HBA, which is reserved, to the identifier of the second virtual HBA, and stores the identifier of the second virtual NIC and the identifier of the second virtual HBA into the first real machine.