Hitachi, Ltd.

Kensuke Narita

Azusa Jin

Takamasa Sato

Takashi Sakaguchi

Yosuke Katoh

Hideo Saito

Atsushi Sutoh

Takashi Nagao

Toru Suzuki

Takahiro Abe

Naoko Ikegaya

Ran Ogata

A storage apparatus and method of controlling same which, while preventing depletion of a storage area due to the generation of garbage, also prevent a drop in response performance from the perspective of the host, are proposed. One or more storage devices which constitute a pool, and a controller which manages a log-structured write space which is a virtual logical space, compresses data of a compression target among the data which has been written to the virtual volume by the host and logs the data in the log-structured write space, and writes the post-compression data which has been logged in the log-structured write space to the storage device, are provided in a storage apparatus, the controller restricting reception of a write request from the host when a used capacity of the pool is at or above a threshold; when the data logged in the log-structured write space has been updated, the controller determines whether a predetermined condition is satisfied and, when the predetermined condition is satisfied, the controller overwrites the compressed data of the pre-update data which has been logged in the log-structured write space with the compressed data of the post-update data.

Storage apparatus and method of controlling same

A storage system forms a high availability pair for data duplication using a first volume of a first storage apparatus as a primary volume and a second volume of a second storage apparatus as a secondary volume. The first volume and a third volume of a third storage apparatus are used as a primary volume and a secondary volume, respectively, to form an asynchronous copy pair. The second volume and the third volume are used as a primary volume and a secondary volume, respectively, to form a standby pair. When a command to form the asynchronous copy pair is received, the storage system refuses to form the asynchronous copy pair when the standby pair is not formed yet.

Storage system

Fault-tolerance is improved by duplicating data and update information of that data. A storage system has a first storage apparatus that is connected to a host computer, and includes a plurality of first data volumes and a first journal volume, a second storage apparatus that is connected to the host computer and the first storage apparatus, and includes a plurality of second data volumes for storing duplicated data of each of the plurality of first data volumes, and a second journal volume for storing the duplicated data of the first journal volume, a third storage apparatus that is connected to the first storage apparatus, and includes a plurality of third data volumes that configure a remote copy pair with the plurality of first data volumes by using the journal data received from the first storage apparatus, and a fourth storage apparatus that is connected to the third storage apparatus.

Storage system and data management method of journaling and storing remote copies

A backup copy from a first data volume to a second data volume is executed according to either a synchronous mode, in which write data is copied from the first data volume to the second data volume in synchronous with a write request, or an asynchronous mode, in which journal data of a first storage apparatus is reflected on the second data volume in asynchronous with the write request. A second storage apparatus acquires secondary load information representing its own load status, and transmits the information to the first storage apparatus. The first storage apparatus acquires primary load information representing its own load status, determines switching between the modes based on the secondary load information, the primary load information and mode information, and transmits determination information representing determination results to the second storage apparatus. When the determination information represents the switching from the asynchronous mode to the synchronous mode, the second storage apparatus acquires the journal data from the first storage apparatus and reflects the journal data on the second data volume.

Backup system

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Tokyo, Japan

Kensuke Narita