Fujitsu Corporation

Hidejiro Daikokuya

Mikio Ito

Kazuhiko Ikeuchi

Hideo Takahashi

Shinya Mochizuki

Norihide Kubota

Yoshihito Konta

Tsukasa Makino

Hiroaki Ochi

Yasutake Satou

Satomi Mamiya

Koji Uchida

Akihito Kobayashi

Yasutake Sato

Hiroyuki Hoshino

Yoshio Kitamura

Minoru Muramatsu

Riichiro Take

Yuuji Hotta

Shinichi Nishizono

Kazuma Takatsu

Hideki Yamanaka

Katsuhiko Nagashima

Yuji Noda

Tadaomi Kato

Yasuhiro Onda

Futoshi Watanabe

A response of a disk device during rebuild can be sped up. A disk array control device determines whether or not there is a normal read request during rebuild. If there is a read request during rebuild, data is read by sequentially switching a plurality of disk devices in a certain block size unit lower than a block size in which each disk device reads data during normal read.

Disk selection method, raid control device, raid system, and its disk device

In a system for dispersively storing data and parity in a plurality of storage devices, information in a first storage device is restored by using information stored in the storage devices other than the first storage device when the first storage device fails. And information in a non-restored area in the first storage device and information in a second storage device are restored by using information stored in the storage devices other than the first and the second storage devices when the second storage device fails while the information in the first storage device is being restored.

Storage control apparatus and method

A RAID apparatus that at least duplicates identical data to store thus duplicated data, which, when an instruction of writing data is given, writes data to a local cache and to a mirror cache, and writes data of the local cache to a primary disk and writes data of the mirror cache to a secondary disk. When an instruction of reading out data is given, and specified data is retained in the caches, the RAID apparatus outputs valid data of the local cache or the mirror cache, while when specified data is not retained in the caches, the RAID apparatus outputs valid data of the primary disk or the secondary disk.

RAID apparatus, RAID control method, and RAID control program

A method and apparatus for enhancing performance of parity check in computer readable media is provided. For example, in a RAID (N+1) configuration, a virtual data strip is added for a calculation of parity. Data of the virtual data strip is set so that a predetermined portion of a data area in the virtual data strip has a predetermined value. Consequently, performance of parity check performed in a data processing system having a RAID configuration can be enhanced.

Method and apparatus for storing a data to memory devices

In case an error statistics of one of the disk drives exceeds a predetermined threshold, the disk is determined as a suspect disk drive. A recovery mode is set successively. During the time when a setting of the recovery mode is in progress and no access is made from a hostin this time, the address range of the suspect disk drive is specified. At the same time, a processing is started in that the data of the suspect disk is copied to a spare disksequentially to recover the data. The data of the suspect disk drive is copied to the spare disk driveto recover the data when the address range of the suspect disk drive does not correspond to the write failure address range of a management table. The data of a normal disk drive is copied to the spare disk driveto recover the data when the address range of the suspect disk drive corresponds to the write failure address range of the management table. Upon the completion of the recovery of the data, the suspect disk driveis separated and replaced with the spare disk drive

Program, storage control method, and storage system

In the present invention, for each set of blocks [#(0) to #(N&#x2212;1)] storing update data, a history block [#(N)] storing an update state value, for example, a generation, time or check code, showing an update state is provided, constituting a set of management data as a check object. When writing update data on a disk, a new update state value is calculated for the same set of management data and stored in memory as update state confirmation value. The new update state value is also set as write data in the history block in the same set of management data, and the entire of the set of management data including update data and update state value are written onto a disk. The history block is read and disk write omissions are detected by comparing the update state value and the update state confirmation value stored in memory.

Apparatus and method for detecting disk write omissions

Storage destination controller devices wherein N number of data strips and M number of parity strips comprised in each stripe are determined so that the parity strips are not continuously stored to the same memory device between two consecutive stripes when a plurality of stripes, each comprising the N number of data strips and the M number of parity strips of different types, are distributed and stored to the N+M number of memory devices.

Storage controller and method for storage control with non-contiguous stored parities

When a write-back request for writing back new data in a cache memory to disk devices forming a redundant configuration of RAID is generated, a write-back processing unit, reserves a parity buffer area in the cache memory, generates new parity, and then, writes the new data and the new parity to the corresponding disk devices. When an error in which the consistency of RAID is broken occurs in a plurality of the disk devices upon write performed by the write-back processing unit, a recovery processing unit reserves, in the cache memory, a cache stripe area storing data of the entire stripe including the new data which is to be written back, and causes the cache control unit to manage it.

Storage system, control method thereof, and program

A RAID control apparatus comprises at least a cache memory; an update information management table for storing update information; an update information storage unit for storing, in the update information management table, update information by detecting a data update; a reference value generation unit for generating a reference value expressing a load of a write back processing by using a Small Write method and a Read & Bandwidth Write method based on the update information; a write method determination unit for determining a write method according to the reference value and a write unit for carrying out a write processing, in order to provide a write back method for a RAID apparatus capable of improving a processing speed at the time of updating even in the case of including the processing of updating a part of data stripes.

Write back method for RAID apparatus

A RAID controller accesses an access request area on logical volumes distributed and stored on a plurality of physical disks according to a disk access request from a host. The controller has a plurality of management modules which are in-charge of plurality of the redundant groups respectively and issuing a logical format request for each area of said logical volume by referring to a management table for managing progress information of the logical format processing. Each management module has a plurality of the management table for being in-charge of said plurality of redundant groups and a queue for queuing the disk access request. The management module, according to the disk access request, judges whether all the access request areas have been logically formatted referring to the management table.

Raid controller and control method thereof

An input/output control apparatus controls input/output requests from a host unit to a plurality of subordinate unit. A priority order managing section in the input/output control apparatus controls a priority order of the input/output requests based on priority orders of the input/output requests given by the host unit, for each of the subordinate units.

Input/output control apparatus, input/output control method and information storage system

A processing method for copying between storage device data regions and a memory system are provided to allow immediate access in a state of having completed copying in response to a copy instruction, even when actual data is being copied in a remote system, thus preventing a decrease in the performance of the access to the copy source during copying. Processes include copying data in a data region of a copy source to an intermediate media data region for each prescribed block unit in response to a copy instruction, as well as copying the data copied to the intermediate media data region to a copy destination data region. Processes also include interrupting copying and processing an access when there is an external access for a block of the copy source or the copy destination data region during the copy processing.

Method for accessing data being copied between data regions before the copying is completed

An input/output scheduling unit forms input/output groups obtained by grouping inputs/outputs to/from a disk apparatus. The input/output scheduling unit defines a ratio of the time during which each input/output group uses the disk apparatus and defines quanta &tgr; to &tgr; during which each input/output group can continuously use the disk apparatus on the basis of the defined time ratios. When input/output requests are received from a plurality of input/output groups to the disk apparatus, the input/output scheduling unit performs the time-sharing for sequentially switching the allocating times &tgr; to &tgr; between the input/output groups which competed and using the disk apparatus. Further, an allocating time of the remaining quanta is distributed to the quanta on the shortage side by an allocating time control unit in accordance with a degree of jam of each input/output group.

Disk time-sharing apparatus and method

A storage controller executes logical format to enable host access to a physical disk, where the logical format of a physical disk is executed without waiting for host access. The storage controller comprises a logical format management module having bit map memory for managing progress information on format processing of a logical volume, and a lower layer module which accesses a physical disk according to the request of the management module. The management module judges whether all the access areas have been formatted referring to the bit map memory, requests the disk access to the lower layer module if judged as formatted, while, issues a logical format processing request before the disk access, queues the disk access request to the queue if not formatted, further searches the unformatted area from the bit map memory, and issues a logical format processing request if no disk access request exists in the queue.

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Kawasaki, Japan

Hidejiro Daikokuya