Disk array device and method of changing the configuration of the disk array device

A disk array adaptable to communicate with an externally located high-order device, the disk array device device comprising:

• a channel adapter that controls data transmission and reception with the high-order device;
• a storage device that stores data;
• a storage device control board to which the storage device is connected;
• a disk adapter that is connected to the storage device via the storage device control board and controls data transmission and reception with the storage device;
• and
• a management unit that is respectively connected to the disk adapter and the channel adapter, wherein
• the storage device control board includes:
• a connection circuit that is connected to the storage device, and
• switch circuits that are respectively disposed at an input side and an output side of the connection circuit and are switchable between a connected mode where they are connected to an adjacent storage device control board and an independent mode where they are separated from the adjacent storage device control board, and
• the switch circuits are switchable between the connected mode and the independent mode by an output signal from the management unit.