Hitachi, Ltd.

Satoshi Oshima

Shinji Kimura

Toshiaki Arai

Hisashi Hashimoto

Masami Hiramatsu

Noboru Sakoyama

Masahide Sato

Hiroshi Mine

Yutaka Enko

Masayoshi Takasugi

A problem with conventional art is that, in an environment wherein a plurality of interrupts having different priorities for processing occur in an overlapping manner from external devices, responding to high-priority interrupts while ensuring execution intervals of periodic tasks has been difficult. A partition execution control device according to the present invention comprises: a first management table which stores, for each partition, initial time slices, remaining time slices, execution priorities, execution states, and an interrupt disable level for suppressing the interrupts from the external devices; and a second management table which stores the interrupt priorities of the external devices and partitions to which the interrupts are to be output. This partition execution control device controls the execution of the partitions using the execution priorities and the time slices stored in the management tables, and controls the execution of the interrupts using the interrupt disable levels and the interrupt priorities.

Realtime hypervisor with priority interrupt support

The present invention provides a technique of controlling cache operation on a node device in a computer system that enables transmission and receipt of data between clients and a storage device via the node device. In accordance with a first control method, the data stored in the storage device includes attribute data, as to whether or not the data is cacheable. This application enables the node device to relay non-cacheable data without process of the cache. In accordance with a second control method, the node device encrypts the data when caching the data in the disk. In accordance with a third control method, non-cacheable data is transmitted and received directly without going through the node device. These applications enable the cache in the node device to be restricted, and thereby ensure security.

Cache control method for node apparatus

A computer system is structured, including a plurality of computers sharing a storage apparatus. The computers each include a control section for determining an access priority based on an attribute of a client computer forwarding an access request. In the control section, the result derived by adding up the priorities is compared with the total value of the priorities calculated by other computers for assignment of an input/output bandwidth. In accordance with the priority assignment, access execution is performed in order of priority. With such a structure, access congestions can be favorably avoided through efficient bandwidth control, and bandwidth assignment can be performed on a server basis in accordance with processes executed by the client computers.

Computer system and bandwidth control method for the same

A service AP conducting ordinary business processing is executed on a first OS. The first OS includes an operation recording controller for recording operation conducted by the first OS as operation recording information together with time when the operation is conducted, and an auxiliary driver for accepting and executing external processing. A multi-OS controller interface included in a second OS, which is higher in reliability than the first OS, operates a multi-OS controller from an AP operating on the second OS. An analysis and prediction AP operating on the second OS analyzes states of the first OS and the service AP, and detects a failure sign. Upon detecting a failure sign, degrade operation of the OS or service AP to be analyzed, preparations for switching from an active system to a stand-by system, and actual switching are conducted before the failure occurs.

Computer system and detecting method for detecting a sign of failure of the computer system

A method for updating information on security , in which the client is connected with a server through a network, the server including a storage device that is managed by the client, the storage device storing security information, the method comprising updating the security information stored in the storage device that the client manages in the server.

Method for updating security information, client, server and management computer therefor

A fault of an operating system (OS) is observed, and in addition to application program (AP) fault monitoring, check-point information is preserved without adding dedicated hardware. In a computer having a multi-OS environment, an AP fault monitor and a monitored AP operate on a first OS. A fault monitor operates on a second OS. Each of the first OS and the AP fault monitor transmits an alive message to the fault monitor by utilizing an inter-OS communication function of a multi-OS controller. The fault monitor monitors the alive message of each of the first OS and the AP fault monitor. The monitored AP also transmits an alive message to the AP fault monitor for monitoring. The monitored AP preserves check-point information in a region of a memory. In the region of the memory, information is preserved by a fault and restart of the first OS as well.

Method for monitoring fault of operating system and application program

The technique of the present invention enhances reading speed of data from a disk device in a computer system capable of transmission and reception of the data via a node devicebetween a clientand a storage device. A share volume PDc and specific volumes PDa and PDb are defined in the disk device on the storage device. Common data among respective clients and specific data corresponding to the individual client are stored in the share volume and specified volumes, respectively. Once respective clients request virtual volumes VDa and VDb to read the data, the storage device reads out the corresponding data from the share volume or the specific volume. This application avoids lowering the reading speed regardless of the concentration of accesses from a plurality of clients because most data can be read from the share volume.

Method and apparatus for a data source device with shared storage for a plurality of clients

A fault of an operating system (hereafter referred to as &ldquo;OS&rdquo;) is observed without adding dedicated hardware. Besides AP fault monitoring, check-point information is preserved at high speed without adding dedicated hardware. In a computer having a multi-OS environment, an AP fault monitor and a monitored AP operate on a first OS. A fault monitor operates on a second OS. Each of the first OS and the AP fault monitor transmits an alive message to the fault monitor by utilizing an inter-OS communication function of a multi-OS controller. The fault monitor monitors the alive message of each of the first OS and the AP fault monitor. The monitored AP transmits an alive message to the AP fault monitor. The AP fault monitor monitors it. The monitored AP preserves check-point information in a region of a memory. In the region of the memory, information is preserved by a fault and restart of the first OS as well.

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Tachikawa, Japan

Satoshi Oshima