Hitachi, Ltd.

Hitachi Information & Telecommunication Engineering, Ltd.

Hitachi Computer Peripherals Co., Ltd.

Hitachi Information & Telecommunications Engineering, Ltd.

Naomitsu Tashiro

Mitsuo Hayasaka

Koji Yamasaki

Hidehisa Arikawa

Taizo Hori

Mikito Ogata

Taketoshi Sakuraba

Motoaki Iwasaki

Tomoki Higuchi

The present invention relates to a storage apparatus that executes de-duplication processing. Specifically, a storage apparatus includes a storing apparatus configured to provide a first storage area and a second storage area and a control unit. The control unit determines, on the basis of a result of comparison of a compression ratio of compressed data with a threshold, whether first duplication determination for determining whether data same as the data compressed without being stored in the first storage area is stored in the second storage area is executed or second duplication determination for determining whether data same as the data compressed after being stored in the first storage area is stored in the second storage area is executed. Further, the control unit changes the threshold on the basis of a state of the storage apparatus.

Storage apparatus and data management method

In a storage system, a controller prevents the same chunk data from being stored in a storage device in an overlapped manner, on the basis of data block information showing an association of each data block and a plurality of chunk data configuring each data block, chunk group information showing an association of each chunk data not to be overlapped and a chunk group which each chunk data belongs to, and reference data block information showing an association of each chunk group and a data block having any chunk data belonging to each chunk group as constituent elements.

Storage system and storage control method

Chunks that commonly occur in each content type are aggregated in a first container. To be more specific, a storage device used for content backup is configured with: (1) a memory device that provides a memory region for one or a plurality of first containers used to store first chunks that commonly occur in each content type among chunks extracted from the contents of writing targets, and for one or a plurality of second containers used to store other chunks than the first chunks; and (2) a backup unit that decides whether each of the chunks extracted from the contents of the writing targets is a first duplication chunk duplicating a chunk stored in the first container, and further decides, for only a chunk that is decided not to be the first duplication chunk, whether each of the chunks is a second duplication chunk duplicating a chunk stored in the second container, and then stores only a chunk that is decided not to be the second duplication chunk in the second container.

Storage device to backup content based on a deduplication system

An optimum chunk cutout method is selected according to the type of content. A storage apparatus is a storage apparatus for storing content in a backup volume in response to a content storage request from a host system connected to the storage apparatus via a network and includes a chunk cutout unit for cutting out the content into one or more chunks and a duplication judgment unit for managing a duplicate state of the chunk or chunks which have been cut out by the chunk cutout unit; wherein the chunk cutout unit selects a method for cutting out the chunk based on content type identification information indicating a type of the content.

Storage apparatus and duplicate data detection method

A cache memory is utilized effectively because data redundancy elimination is executed. A controller manages the cache memory by dividing it into a first area and a second area. When receiving a write access request from an access requestor, the controller divides a data block, which is an access target, into a plurality of chunks and searches the first area first and then the storage apparatus based on each chunk. If chunk storage information, indicating that each chunk is stored in the storage apparatus, does not exist in the first area or the storage apparatus, the controller executes chunk storage processing and creates and stores the chunk storage information. If the chunk storage information exists, the controller eliminates the chunk storage processing for storing the chunks. If the chunk storage information does not exist in the first area, the controller stages the chunk storage information from the storage apparatus to the first area on condition that the first area has an unused area.

Storage system and data processing method using cache memory

A data management system respectively computes first hash values while sliding a window a prescribed amount at a time with respect to a prescribed range from a start location of a data block to a prescribed size. The system extracts, from among the first hash values, a first hash value, which is equivalent to a characteristic value, and partitions the data block into a first chunk of data at a location corresponding to this first hash value. The system determines coincidence between a first chunk of data and a stored second chunk of data, and prevents duplicate data from being stored twice.

Data management method and data management system

A data management system and data management method capable of inhibiting an increase of I/Os caused by deduplication are provided. Data blocks are managed by grouping them; a plurality of chunks belonging to the same group after deduplication are collectively managed as a chunk data set; and if a host system issues a data block deletion request, garbage collection of the relevant chunk data set is performed based on the number of times of references of the chunk data set and the chunk data set after the garbage collection is managed by overwriting the existing chunk data set with a new chunk data set composed of only chunks of data blocks which are not deleted.

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Oi, Japan

Naomitsu Tashiro