Storage system

Abstract

A plurality of storage nodes are connected via a network to build a storage system. Each of the storage nodes includes a storage device. A condition holding unit holds a state condition indicating an inactive state and an active state of the storage device. A state control unit controls a state of the storage device between the inactive state and the active state based on the state condition held by the condition holding unit.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic for explaining the concept of a storage system according to an embodiment of the present invention;

FIG. 2 is a block diagram for explaining a structure of the storage system shown in FIG. 1;

FIG. 3 is an example of the contents of a state-condition table;

FIG. 4 is an example of the contents of a table of a request to be accepted by a controller shown in FIG. 2;

FIG. 5 is an example of the contents of an internal-state table for the controller; and

FIG. 6 is a flowchart for explaining an operation procedure of the controller.

Claims

1. A storage system comprising: a plurality of storage nodes connected via a network to build the storage system, each of the storage nodes including a storage device;a condition holding unit that holds a state condition indicating an inactive state and an active state of the storage device; anda state control unit that controls a state of the storage device between the inactive state and the active state based on the state condition held by the condition holding unit.

2. The storage system according to claim 1, wherein the storage node includes an access-request managing unit that manages, when a local storage device is controlled to be in the active state by the state control unit, an access request to other storage device that is controlled to be in the inactive state by the state control unit.

3. The storage system according to claim 2, wherein the storage node further includes a data storing unit that receives, when the local storage device is controlled to be in the active state by the state control unit, data having a high incidence of read-out from the other storage device, and stores the received data, whereinthe access-request managing unit reads out, when there is a read-out request with respect to the other storage device, data corresponding to the read-out request from the data storing unit, and transmits the read data to a request source of the read-out request.

4. The storage system according to claim 2, wherein the storage node further includes a temporary storing unit that temporarily stores, when the local storage device is controlled to be in the active state by the state control unit, data that is to be written to the other storage device, whereinthe access-request managing unit temporarily stores, when there is a write request with respect to the other storage device, data corresponding to the write request to the temporary storing unit, and when a predetermined transfer condition is satisfied, transfers the data corresponding to the write request stored in the temporary data storing unit to the other storage device.