Hitachi, Ltd.

Hitachi Microcomputer System, Ltd.

Hitachi Microcomputer Engineering, Ltd.

Microcomputer Engineering Ltd.

Toshiaki Tsuboi

Akira Yamamoto

Hiroyuki Kitajima

Shigeo Honma

Yoshihiro Asaka

Michio Miyazaki

Koji Ozawa

Toshio Nakano

Shigeru Kishiro

Takao Sato

Katsunori Nakamura

Masafumi Nozawa

Akira Kurano

Takashi Sumiyoshi

Yoshiaki Kuwahara

Yoshiro Shiroyanagi

Kosaku Kambayashi

Sadasaburoh Kanai

In allocating an area of a cache memory to each storage unit, proper allocation of the cache memory is made to each storage unit. If the amount of write-after data becomes equal to or more than a threshold value, an allocation limit is set to each disk unit. If CPU issues a data write request requiring the amount of data equal to or more than the allocation limit, the data write request is held in a wait state until the amount of write-after data becomes less than the allocation limit. Therefore, the allocation amount to the disk unit becomes neither too large nor too small. In this manner, proper allocation of the cache memory to each disk unit can be realized.

Controller limiting modification of cache based upon amount of dirty

An information processing system has a processor, a first storage unit, a controller connected between said processor and said first storage unit, and a second storage unit connected to said processor and for storing dump data, and a dump method thereof are disclosed. The controller manages updated regions of the first storage unit as write regions. In response to a dump request issued by the processor, the controller manages regions which are managed as the write regions and included in a dump portion as protected regions. If a write request for a region which is managed as protected region, the controller saves contents of the region to dump point file before executing a write operation, and release the region from the protected regions. The controller transfers contents of regions managed as protected track and contents of the dump point file to the processor as contents of regions to be dumped. At the end of dump processing, the controller deletes the dump point file and terminates management of the protected regions.

Dumping method for dumping data to a dump data storage device that

A data processing system for processing transactions, wherein a log record to be used for recovery of the system is written into a log file for system recovery in synchronism with the end of a transaction, and log records other than resident information are is written for a plurality of transactions into a log file for archives.

Method and a system for processing a log record

Limiting modification of cache entries in a write-back cache based upon

Controller for storage unit and method of controlling storage unit

An input/output control apparatus connected to a plurality of input/output units such as disc systems and an input/output control method. A cache memory is divided into a plurality of storage areas for data management. Data stored in the disc systems are stored in the storage areas. In response to an output request from a HOST system to the disc systems, data outputted from the latter are stored in the storage areas of the cache memory. The data stored in the storage areas and outputted therefrom in response to the output request are transferred to the disc systems. The storage areas storing the data requested and not yet stored in the disc systems are grouped correspondingly to the disc systems where the output data are to be stored. The resulting group is managed as a first attribute group. Write-after processing for every disc units can be executed in parallel efficiently without involving high processing overhead.

Input/output control method and system

In a control unit having a external storage device, a method for selecting a loading method of data stored in the cache memory into the cache memory in accordance with an access pattern to the data, and an apparatus therefor are disclosed. The selection of the loading method is selection of control mode or procedure in accordance with the loading method, and it is attained by a learn function.

Memory controller with a cache memory and control method of cache memory

Growing community of inventors

Kawasaki, Japan

Toshiaki Tsuboi