Abstract: A storage device controller including: channel control portions each including a circuit board on which a file access processing portion for receiving file-by-file data input/output requests sent from information processors and an I/O processor for outputting I/O requests corresponding to the data input/output requests to storage devices are formed, the channel control portions being classified into groups for the sake of fail-over; and a device for storing data updated by each of the channel control portions and handed over at the time of the fail-over in a shared volume which is a storage region logically set on physical storage regions provided by the storage devices and which can be accessed commonly by any other channel control portion belonging to the same group as the channel control portion updating the data.

Abstract: In a storage system, a judgment is made as to whether respective programs installed in storage regions assigned to a plurality of channel control portions exchanging data input/output requests based on designated filenames with information processors connected to the storage system through a network are licensed or not. When a decision is made that the respective programs are licensed, the programs installed in the channel control portions in the storage system are managed to be controlled to be enabled to be used.

Abstract: A storage system including: channel control portions each including a circuit board on which a file access processing portion for receiving file-by-file data input/output requests sent from information processors through a network and an I/O processor for outputting I/O requests corresponding to the data input/output requests to storage devices are formed; disk control portions for performing data input/output of the storage devices in response to the I/O requests sent from the I/O processors; and a computer communicatably connected to the channel control portions and the disk control portions. The storage system is formed so that when one of the channel control portions detects occurrence of failure in the channel control portion, the channel control portion gives a notice of occurrence of failure to the computer.

Abstract: A cryogenic refrigerator includes a displacer and a cylinder therein for generating a very low temperature. And, a sealing ring is provided in an inserted condition within a ring shaped groove which is formed at an outer peripheral portion of the displacer, the sealing ring having resilience for extending itself outward so that a sealing member on an outer diameter thereof is enlarged and that an outer portion of the sealing ring is slidably contacted to an inner face of the cylinder, and the sealing ring being made of non-magnetic alloy, thereby a magnetic noise and disturbance of an outer magnetic field due to the cryogenic refrigerator are greatly decreased.