Hitachi, Ltd.

Masaharu Akatsu

Tomohiro Murata

Norifumi Nishikawa

Hironori Emaru

Shunsuke Akifuji

Tetsuo Tanaka

Kenzo Kurihara

Akihiro Yoshikawa

Gou Kojima

Akira Yamamoto

Shigeo Homma

Shigeo Honma

Koji Ozawa

Yoshiaki Kuwahara

Morihiko Yotsuya

Kenzou Kurihara

The present invention provides a performance monitoring method of a processing flow that, in a distributed object system, a processing is completed after going by way of processing of several objects through objects. A collector collects, as performance data, a receiving time of a message from the other object and a sending time of a message to the other for an object that becomes a measurement target on each computer. A manager puts received performance data together and calculates and displays a processing time of each object that constitutes a processing flow and a communication time between objects.

Performance monitoring method in a distributed processing system

A disc controller, which is connected to a plurality of channels for supplying access requests and discs. The controller includes a plurality of storage paths which control transfer of data between a cache, the channels and the discs, and a control memory which controls the respective operations of the plurality of storage paths. The control memory stores information which is used to select a storage path in accordance with predetermined standards for storage path selection. A disc or the cache is accessed using the selected storage path.

Disc access control method for cache-embedded disc control apparatus

In order for a disk control unit with built-in cache to write non-reflective data in the cache to a disk drive without stopping extension of a read/write command from host computer in the event of a fault in the cache or its backup memory, the track data in normal one of the cache and its backup memory is written to a certain physical track of the disk drive upon judging at read/write command execution that the accessed track is a non-reflective track, and a read/write command from the host computer is implemented for the physical track of the disk drive which has completed the non-reflective track write operation.

Method of fault handling for a disk control unit with built-in cache

Herein disclosed is a disk controller having a cache. This cache is so managed that a predetermined part composed of at least one of a plurality parts divided therefrom is initialized. In response to a request for cache activation from a host computer, the initializations of the cache are partly executed in a repeated manner, and a request for disk input/output is intermittently processed so that the whole initializations of a cache having a large capacity can be executed in parallel with the online process. Moreover, the logic failure of the cache and the hardware failure of a memory are divided. When the logic failure occurs, the use of the case is temporarily prohibited, and the whole initializations of the cache are executed automatically at the side of the disk controller without any intervention of a maintenance man so that the cache can be used again.

Method of and apparatus for automatic recovery of a cache in a storage

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Yokohama, Japan

Masaharu Akatsu