Abstract: Embodiments of the invention improve the security of data written on a magnetic disk by performing re-allocation processing starting from a sector whose defect is large in automatic re-allocation processing. According to one embodiment of the present invention, after the reliability of each of data sectors that have been read out from a magnetic disk according to a read command is determined, re-allocation processing on the data sectors is performed in the order of increasing reliability. As a result, within a limited period of time, it is possible to replace by priority a data sector where there is a high possibility that data recovery will be unable to be achieved. This makes it possible to increase the security of data and the reliability of the HDD. The reliability of each data sector is determined on the basis of the number of bytes corrected by ECC.

Abstract: Embodiments in accordance with the present invention relate to determination of a connecting status of a device in a system constituted by a plurality of devices connected via information transmission path in a loop, such as fibre channel arbitrated loop. Particular embodiments of the present invention may help to prevent a bypassed device from performing an improper process at a loop initialization process. According to one embodiment, each device checks its own bypass status at a loop initialization process. The device which has become a loop master determines that it is not bypassed by itself. In an address obtaining step, the device checks whether or not the device itself can actually obtain the address which the device tried to obtain by means of a bit map of the received frame and determines that the device is not bypassed if the address is not obtained. The device checks whether or not the address which has been stored in a predetermined position of a position map exists.

Abstract: Embodiments of the present invention provide a loop network system and data storage devices connected thereto where the data storage devices (nodes) can perform effective pieces of processing and the probability of error occurrence can be reduced. One embodiment according to the present invention includes a Fibre Channel Arbitrated Loop network, a Host controller and multiple HDDs connected thereto. A port on the network outputs parameters to control loop initialization processing as well as a LIP Order Set. Each port performs loop initialization processing according to the received parameters and transfers the received LIP Order Set with parameters appended to the down stream.

Abstract: Embodiments of the invention improve the security of data written on a magnetic disk by performing re-allocation processing starting from a sector whose defect is large in automatic re-allocation processing. According to one embodiment of the present invention, after the reliability of each of data sectors that have been read out from a magnetic disk according to a read command is determined, re-allocation processing on the data sectors is performed in the order of increasing reliability. As a result, within a limited period of time, it is possible to replace by priority a data sector where there is a high possibility that data recovery will be unable to be achieved. This makes it possible to increase the security of data and the reliability of the HDD. The reliability of each data sector is determined on the basis of the number of bytes corrected by ECC.