Hitachi, Ltd.

Katsumi Hirezaki

Koji Nagata

Yosuke Murakami

Yoshiaki Eguchi

Takahiro Nakano

Koji Sonoda

Akira Murotani

Takashi Horiuchi

Nobuyuki Saika

Tetsuya Shirogane

Tsuyoshi Inoue

In a storage system, a real page is allocated from a pool to a write destination virtual page in a virtual volume. The real page includes multiple real regions. The storage system moves all valid data stored in two or more move-source real pages respectively allocated to two or more virtual pages, to move-destination real pages the number of which is less than the number of move-source real pages in units of real regions. Each piece of valid data can be used by any one of the access sources. The storage system writes the predetermined data to all move-source real regions in each of move-source real pages, so that each of the move-source real pages is set as a recovery target real page which is a real page storing only the predetermined data, and performs real capacity recovery for making each recovery target real page into an unallocated state.

Computer system and method for allocating and recovering virtual volumes

A controller unit, a plurality of storage devices, a log area, and a normal area are provided. A quantity of log storage devices forming the log area is smaller than a quantity of normal storage devices forming the normal area. In an operational period, in which the controller unit may accept an input-output command, a power consumption condition of the log storage devices is constantly in a normal condition in which an input or output of data can be carried out, while a power consumption condition of the normal storage devices is in an energy saving condition in which a power consumption is lower than in the normal condition. The controller unit, when receiving the input-output command if the power consumption condition of the normal storage devices is the normal condition, carries out an input or output with respect to both the normal area and the log area.

Storage system including energy saving function

Data is managed efficiently by switching between block level hierarchical control and file level hierarchical control according to file characteristics. A storage apparatus which is connected via a network to a host computer which requests data writing comprises storage media of a plurality of types of varying performance, a volume management unit which manages storage areas provided by the storage media of the plurality of types as different storage tiers and manages storage tiers of the same type or different types as a pool and provides predetermined areas of the pool to the host computer as volumes, and a file management unit which constructs file systems, for managing data in file units configured from a plurality of blocks, in the volumes, and receives file unit data write requests from the host computer.

Storage apparatus and data management method

[Problem] Providing a storage apparatus and a snapshot control method for the same for preventing, even after long-term operation of snapshots as a means for backup, an increase in the amount of pre-update data retained in a differential volume. [Solution] According to this invention, snapshots utilizing pre-update data are replaced with snapshots utilizing update data so that the areas, in the differential volume, storing the pre-update data are released as free areas correspondingly, thereby avoiding accumulation of the pre-update data in the differential volume.

Storage apparatus and snapshot control method of the same

When power to a storage device is turned on and the storage device can accept a data input and output request being transmitted from an information processing device, the storage device transmits a power-on request for turning on power to the information processing device. The storage device, when it accepts a stop-power instruction, transmits a stop-power request for stopping power to the information processing device.

Control method of storage system, storage system, and storage apparatus

Snapshots are implemented by combining original data in a place where an operational volume has been updated with data in a place where the operational volume has not been updated. A snapshot management table maintains a value indicating that update has not been conducted, or a storage place of original data, for each of combinations of blocks in the operational volume and the snapshots. If there is a snapshot in which update has not been conducted in a update place at the time of update, then original data is copied and the snapshot management table is updated. The copied original data is managed by a difference block management table, which has a value indicating whether respective snapshots are referencing the data. If a snapshot is deleted, then the value indicating that the snapshot is referencing is altered in all entries in the difference block management table.

Method of maintaining a plurality of snapshots, server apparatus and storage apparatus

The present invention suppresses the generation of redundant I/O and improves the response to the host during data migration. When migrating data from the migration source volume to the migration destination volume, the access destination of the host is switched to the second storage device. When data requested by the host has not yet been migrated, data is read from the first storage device. When the frequency of access to the non-migrated area reaches a prescribed value, the target IP address is changed and discovery is implemented so as to switch the access destination of the host to the first storage device. When the frequency of access to the migrated area in the first storage device reaches a prescribed value, the access destination of the host is switched to the second storage device. The access destination of the host is controlled based on the data migration state and access state, and the generation of redundant I/O can be suppressed.

Growing community of inventors

Odawara, Japan

Katsumi Hirezaki