Abstract: A network storage includes at least one host device, a plurality of disk array devices, an address map that is stored in one of the plurality of disk array devices and indicates a correspondence relation between a logical address to view the plurality of disk array devices as one storage device and a physical address of each of the plurality of disk array devices, a management master that is included in the host device or one of the plurality of disk array devices, an address map storing location information that is stored in the management master and indicates the disk array device that stores the address map and an address on which the address map is stored in the disk array device, and a command management unit that is included in the management master and transmits the address map storing location information to the host device.

Abstract: A power supply apparatus includes a power supply part including a plurality of power supply units, a first comparison unit comparing a first voltage of the power supply part with a first reference value, a directing unit issuing a voltage fall direction to one of the power supply units so as to lower a voltage setting value when the first voltage is higher than the first reference value, a second comparison unit comparing a second voltage of the power supply unit obtained after the voltage fall direction is issued with the second reference voltage value, and a determining unit determining that the power supply unit to which the voltage fall direction issued corresponds to a failure unit, when the second comparison unit detects that the second voltage obtained after the voltage fall direction is issued fell in the voltage level lower than the second reference voltage.

Abstract: A power supply apparatus includes a power supply part including a plurality of power supply units, a first comparison unit comparing a first voltage of the power supply part with a first reference value, a directing unit issuing a voltage fall direction to one of the power supply units so as to lower a voltage setting value when the first voltage is higher than the first reference value, a second comparison unit comparing a second voltage of the power supply unit obtained after the voltage fall direction is issued with the second reference voltage value, and a determining unit determining that the power supply unit to which the voltage fall direction issued corresponds to a failure unit, when the second comparison unit detects that the second voltage obtained after the voltage fall direction is issued fell in the voltage level lower than the second reference voltage.

Abstract: A network storage includes at least one host device, a plurality of disk array devices, an address map that is stored in one of the plurality of disk array devices and indicates a correspondence relation between a logical address to view the plurality of disk array devices as one storage device and a physical address of each of the plurality of disk array devices, a management master that is included in the host device or one of the plurality of disk array devices, an address map storing location information that is stored in the management master and indicates the disk array device that stores the address map and an address on which the address map is stored in the disk array device, and a command management unit that is included in the management master and transmits the address map storing location information to the host device.

Abstract: A magnetic disk apparatus includes a plurality of hard disk drives (HDDs) and a decoder for transforming logical addresses received from a host to physical addresses respectively assigned to the HDDs. The HDDs each have a magnetic disk section including at least one magnetic disk for storing data, a magnetic head section for selectively writing or reading data in or out of the magnetic disk section, and a drive control for controllably driving the magnetic head section in accordance with the physical addresses output from the decoder. The decoder has a function for transforming the logical addresses of a diagnosis command received from the host to the physical addresses of the HDDs while the drive control has a function of controlling a write/read test with the physical addresses produced by the function of the decoder. The decoder further has a function of setting the physical addressees of the radially innermost cylinders of the HDDs as the physical addresses to be diagnosed.

Abstract: A method of controlling data transfer through a system bus between units in a computer system employs a split transfer technique that transfers data transfer requests separately from responses to the requests. The method provides one of the units with a bus grant signal to allow the unit to transfer a plurality of transferrable statuses to another unit that has requested them.