Hitachi, Ltd.

Lapis Semiconductor Co., Ltd.

Naohiro Fujii

Nobuyuki Saika

Naoto Ueda

Motoaki Satoyama

Koji Honami

Takahiro Nakano

Keiichi Matsuzawa

Yuki Imatoh

Yutaka Enko

A signal processing circuit has: n+1 (n being an integer of 2 or greater) operation circuits, each of which is configured to execute a prescribed operation process on inputted data; a signal supply unit that is configured to receive n pieces of input data extracted from one input signal and receive test data inputted separately from the n pieces of input data, sequentially select one operation circuit among the n+1 operation circuits and supply the test data to the one selected operation circuit, and supply the n pieces of input data to n operation circuits other than the one operation circuit among the n+1 operation circuits; and an anomaly determination unit that is configured to determine whether an anomaly has occurred in the one operation circuit on the basis of an operation result of an operation on the test data by the one operation circuit.

Signal processing circuit

A high-performance and highly-reliable snapshot management apparatus and method, and a storage system are provided that can prevent the adverse influence of overhead when they retain a multiplicity of snapshots. An operational volume is set in a storage area provided by a first storage apparatus and a plurality difference volumes are set in a storage area provided by a second storage apparatus. In response to data writing to the operational volume, difference data is saved in the difference volumes and management tables for it are created, with each snapshot being managed according to the management tables. Each management table is divided according to one or more snapshots in accordance with the snapshot creation time. The second and any following management tables store specified inheritance information to inherit the content of the preceding management tables.

Snapshot management apparatus and method, and storage system

Proposed are a backup apparatus and a backup method capable of improving the backup performance, as well as a file reading apparatus capable of improving the file reading performance. As a result of determining a read sequence upon reading the respective files from a disk device based on a physical address of the respective storage areas storing data of each of the files in the disk device, and sequentially reading data of each of the files from the disk device according to the determined read sequence, overhead such as the head seek and rotational delay in the disk device upon reading a plurality of files from such disk device can be dramatically reduced.

Backup apparatus, backup method, and file reading apparatus

A high-performance and highly-reliable snapshot management apparatus and method, and storage system are provided that can prevent the adverse influence of overhead when they retain a multiplicity of snapshots. An operational volume is set in a storage area provided by a first storage apparatus and a plurality difference volumes are set in a storage area provided by a second storage apparatus. In response to data writing to the operational volume, difference data is saved in the difference volumes and management tables for it are created, with each snapshot being managed according to the management tables. Each management table is divided according to one or more snapshots in accordance with the snapshot creation time. The second and any following management tables store specified inheritance information to inherit the content of the preceding management tables.

In a network system in which clients and file servers are connected by networks and a client makes access to a file stored in a disk storage device of a file server via the networks, accessibility to a file of a file server distant from the client tends to be deteriorated. In order to resolve the problem, the file server having the file searches for an appropriate file server in the proximity of the client and transfers the file to the appropriate file server (migration target server). Thereafter, the client makes access to the migration target server for the file.

File migration device

A backup method is provided for use with a storage system composed of a memory which stores a control program, a disk drive having an primary volume, a differential volume, and mapping information, the primary volume storing data sent from a client, the differential volume storing differential data of a snapshot of the primary volume, the mapping information managing the relation between data stored in the primary volume and differential data stored in the differential volume, and a control processor which controls read and write of data in the disk drive. The mapping information is referred to compose the data stored in the primary volume and the differential data stored in the differential volume. The composed data is sent to a backup device.

Backup method, storage system, and program for backup

A first data transfer module sends update data to be written into a primary volume to a second data transfer module; the second data transfer module stores the update data into a secondary volume, stores differential data written to a storage address for the update data in the secondary volume into a second differential volume, updates a second management information holding module, and then informs completion of the data updating to the first data transfer module; and the first data transfer module stores the update data to an update address in the primary volume when the information of completion of the data updating is received from the second data transfer module, stores the differential data into a first differential volume, and updates a first management information holding module.

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Yokohama, Japan

Naohiro Fujii