Abstract: An access control apparatus includes a memory, and a processor coupled to the memory and configured to, in response to an access request to a storage device, output an access command through a first path to a first controller among a plurality of controllers that control the storage device, the access command being a command to access the storage device, when no response to the access command to the first controller is received before a predetermined time passes after the output of the access command, control a second controller different from the first controller among the plurality of controllers through a second path coupled to the second controller such that the second controller stops processing executed by the first controller according to the access command, and output the access command through the second path after receiving a response to the control on the second controller.

Abstract: An information processing apparatus is connected through a plurality of paths to a plurality of controllers included in a storage device and includes a processor. The processor is configured to issue, to the storage device, an inquiry about a recommended path through which a data access command is to be issued to the storage device. The processor is configured to compare a delay predictive time with a response predictive time in regard to the data access command. The delay predictive time is a predictive value of a delay time due to a data communication using an inter-controller communication between the plurality of controllers. The response predictive time is a predictive value of a response time when the inquiry is issued to the storage device. The processor is configured to suppress the issuance of the inquiry when the response predictive time is equal to or longer than the delay predictive time.

Abstract: An access control apparatus includes a memory, and a processor coupled to the memory and configured to, in response to an access request to a storage device, output an access command through a first path to a first controller among a plurality of controllers that control the storage device, the access command being a command to access the storage device, when no response to the access command to the first controller is received before a predetermined time passes after the output of the access command, control a second controller different from the first controller among the plurality of controllers through a second path coupled to the second controller such that the second controller stops processing executed by the first controller according to the access command, and output the access command through the second path after receiving a response to the control on the second controller.

Abstract: An information processing apparatus is connected through a plurality of paths to a plurality of controllers included in a storage device and includes a processor. The processor is configured to issue, to the storage device, an inquiry about a recommended path through which a data access command is to be issued to the storage device. The processor is configured to compare a delay predictive time with a response predictive time in regard to the data access command. The delay predictive time is a predictive value of a delay time due to a data communication using an inter-controller communication between the plurality of controllers. The response predictive time is a predictive value of a response time when the inquiry is issued to the storage device. The processor is configured to suppress the issuance of the inquiry when the response predictive time is equal to or longer than the delay predictive time.

Abstract: An input and output method includes connecting a storage apparatus to an information processing apparatus via a plurality of paths, storing management information for a timeout time of each of the plurality of paths in a storage unit of the storage apparatus, and acquiring the timeout time of a path and another path of an input/output issuance destination for the storage apparatus from the storage unit depending on the path and the another path.

Abstract: An influence determination unit configured to determine whether each path in a network system is a prospective to be affected path affected by maintenance work or a prospective to be unaffected path not affected by the maintenance work by referring to path management information, a path influence information output unit configured to output a diagnosis result to a plurality of processing apparatuses as path influence information about each of the paths, a maintenance possibility diagnosis unit configured to conduct a diagnosis on whether the maintenance work is performable based on the path influence information of the paths connected, and a maintenance possibility information output unit configured to output the diagnosis result as maintenance possibility information is included, wherein maintenance work efficiency is improved in the network system by outputting permission information indicating permission or refusal of the maintenance work for maintenance object components based on the maintenance possibili

Abstract: An input and output method includes connecting a storage apparatus to an information processing apparatus via a plurality of paths, storing management information for a timeout time of each of the plurality of paths in a storage unit of the storage apparatus, and acquiring the timeout time of a path and another path of an input/output issuance destination for the storage apparatus from the storage unit depending on the path and the another path.

Abstract: A method for controlling a storage apparatus connectable to a server, the storage apparatus including a first storage area and a second storage area for storing data, the method comprises: copying the data stored in the first storage area into the second storage area; copying data stored in the location of the first storage area addressed by the command to be accessed by the server into the location of the second storage area before execution of the command when the storage apparatus receives a command for accessing data stored in a location of either of the first storage area and second storage area from the server; and executing the command for accessing at least one of the location in the first storage area and the corresponding location in the second storage area.

Abstract: A method for controlling a storage apparatus connectable to a server, the storage apparatus including a first storage area and a second storage area for storing data, the method comprises: copying the data stored in the first storage area into the second storage area; copying data stored in the location of the first storage area addressed by the command to be accessed by the server into the location of the second storage area before execution of the command when the storage apparatus receives a command for accessing data stored in a location of either of the first storage area and second storage area from the server; and executing the command for accessing at least one of the location in the first storage area and the corresponding location in the second storage area.