Abstract: In order to reduce IO processing delay when information transmitted and received between a server and a storage device via a fiber channel line is lost, after receiving, from the transmission source via the fiber channel line, identification information assigned to an information group transmitted by a transmission source, when it is determined, on the basis of the identification information, that at least part of the information group has not been received, the communication device transmits prescribed transmission information to the transmission source via the fiber channel line.

Abstract: In some embodiments, a storage system may include, but is not limited to, a master volume, one or more link volumes, a master data read frequency determination unit, a load state determination unit, a copy target determination unit, a copy destination determination unit, and a copy controller. The copy target determination unit determines copy target data in the data stored in the master volume on the basis of the read frequency when the load state determination unit determines that the master volume is in a high load state. The copy destination determination unit determines at least one of the one or more link volumes as a copy destination link volume of the copy target data on the basis of the load state of each of the one or more link volumes. The copy controller copies the copy target data into the copy destination link volume.

Abstract: A storage device is communicably connected to a host through a network switch on a network. The storage device includes a disk array having a storage medium storing data, and a plurality of controller units each having a port for connection to the network and controlling I/O process for the disk array. A first controller unit carries out a first setting to send, to the first controller unit, the packets sent by the host to a second controller unit, and a second setting to let the host regard at least part of the packets sent by the first controller unit to the host as are sent by the second controller unit, for the network switch.

Abstract: A storage device is communicably connected to a host through a network switch on a network. The storage device includes a disk array having a storage medium storing data, and a plurality of controller units each having a port for connection to the network and controlling I/O process for the disk array. A first controller unit carries out a first setting to send, to the first controller unit, the packets sent by the host to a second controller unit, and a second setting to let the host regard at least part of the packets sent by the first controller unit to the host as are sent by the second controller unit, for the network switch.

Abstract: To prevent random access commands from remaining even in the case of mixed sequential and random accesses. A storage medium control unit is used in a data storage device adapted to perform processing on a data storage medium based on multiple requests including sequential access requests and random access requests. The storage medium control unit includes: request response delay monitoring device for monitoring the presence of delay in response to the requests based on whether or not the response time for each request exceeds a certain allowable delay time; and request control device for preventing the rearrangement processing of the sequential access requests and controlling the processing of the requests to be performed in a certain request order at the allowable delay time if exceeded.

Abstract: To prevent random access commands from remaining even in the case of mixed sequential and random accesses. A storage medium control unit is used in a data storage device adapted to perform processing on a data storage medium based on multiple requests including sequential access requests and random access requests. The storage medium control unit includes: request response delay monitoring device for monitoring the presence of delay in response to the requests based on whether or not the response time for each request exceeds a certain allowable delay time; and request control device for preventing the rearrangement processing of the sequential access requests and controlling the processing of the requests to be performed in a certain request order at the allowable delay time if exceeded.

Abstract: An information recording apparatus according to the present invention manages a priority value for each host that can log in, and allocates an immediate data buffer to each host based on the priority value. The priority value changes in accordance with data transfer amount, command importance degree, etc. The information recording apparatus recalculates the priority value regularly or arbitrary, and re-performs login negotiation by requesting re-login to the hosts. The amount of buffer allocated is dynamically changed by this login negotiation, and a buffer allocation state best suited to each occasion is built. Since the present invention can dynamically determine or change the allocation amount of the immediate data buffer in accordance with the condition of each occasion, the performance of an iSCSI apparatus can be improved.

Abstract: An information recording apparatus according to the present invention manages a priority value for each host that can log in, and allocates an immediate data buffer to each host based on the priority value. The priority value changes in accordance with data transfer amount, command importance degree, etc. The information recording apparatus recalculates the priority value regularly or arbitrary, and re-performs login negotiation by requesting re-login to the hosts. The amount of buffer allocated is dynamically changed by this login negotiation, and a buffer allocation state best suited to each occasion is built. Since the present invention can dynamically determine or change the allocation amount of the immediate data buffer in accordance with the condition of each occasion, the performance of an iSCSI apparatus can be improved.