Fujitsu Corporation

Akira Ban

Takashi Murayama

Ryota Tsukahara

Takaaki Yamato

Nobuyuki Hirashima

Katsuo Enohara

Teruji Yamakawa

Fumio Matsuo

Toshiaki Takeuchi

Takuya Kurihara

Kiyomi Imamura

Yutaka Horiguchi

Hiroshi Ichii

A storage device includes: a plurality of first storage devices; a second storage device; and a control device to use the plurality of first storage devices as a primary storage and the second storage device as a secondary storage, control access processing to a plurality of logical volumes each of which indicates a virtual recording medium, register a logical volume for which a mount request is made within a predetermined period of time among the plurality of logical volumes in an management information as the logical volume which belongs to the same group, and allocate a storage area of the primary storage corresponding to each of a plurality of registered logical volumes which belong to a group registered in the management information to any one of the plurality of first storage devices such that an allocation destination of the storage area is distributed among the plurality of first storage devices.

Storage device and storage control method

A rotation control method controls rotation of a CAV system recording medium which has a plurality of zones divided in a radial direction thereof. The rotation control method detects a state within a memory which temporarily stores write data to be written on the recording medium and/or read data read from the recording medium, and switches and controls a rotational speed of the recording medium based on the detected state of the memory, depending on an area which is accessed of a plurality of areas of the recording medium dividing the recording medium in the radial direction thereof.

Rotation control method for CAV system based on sequential or random access request and on zone access based on access request of recording medium

When a write access is received from an upper apparatus, a cache control unit develops write data into a data buffer area in a memory, notifies the upper apparatus of a normal end, and thereafter, writes the write data developed into the data buffer area onto a storing medium. An access kind discriminating unit analyzes whether the write access from the host is a sequential access or a random access. A buffer construction control unit selects a data buffer construction of the optimum number of sections in accordance with an access kind and executes the caching operation.

Storing apparatus having a dynamic buffer for random or sequential access

In a storage device in which data is read ahead and stored in a cache memory during reading of data from a medium, a data buffer is managed so that the probability that data to be read is found in the cache memory will improve. The memory area in the cache memory is divided so that a DIR-associated data buffer area used to store a leading address and file name of each file, a FAT-associated data buffer area used to store an address of each file in the next sector, and a data division-associated data buffer area used to store data can all be defined. Addresses referring to the FAT-associated data buffer area and DIR-associated data buffer area are fixed. As a result, as more and more data is read, more and more valid data corresponding to the data residing in the FAT and DIR in a storage medium is found in the cache memory. Consequently, when data reading is requested, data can be transferred without the necessity of reading the storage medium. This results in a shortened reading time.

Storage device having data buffer

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Yokohama, Japan

Akira Ban