DISTRIBUTED STORAGE SYSTEM AND METHOD

• US 20150278018A1
• Filed: 03/13/2015
• Published: 10/01/2015
• Est. Priority Date: 03/29/2014
• Status: Active Grant

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: KATO, Jun
• Granted Patent: US 9,690,658 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 11/1076 Parity data used in redundant arrays of independent storages, e.g. in RAID systems
• CPC Class Codes: G06F 2211/1028 Distributed, i.e. distributed RAID systems with parity

Abstract

A distributed storage system includes a plurality of storage devices and an information processing devices including a storage unit that is accessed more preferentially than the plurality of storage devices, and a processor. The processor deletes the data that can be restored from the storage unit when data that belongs to data stored in a first storage device and which can be restored is stored in the storage unit. The processor writes data that belongs to the data stored in the first storage device and which will not be restored to the storage unit. The processor switches the first storage device to the power-off state after writing the data. The processor reads the data that has been stored in the storage unit and which will not be restored when a request to read the data that will not be restored is given.

Claims

1. A distributed storage system, comprising:

a plurality of storage devices; and

an information processing device;

wherein

the information processing device includes;

a storage unit that is accessed more preferentially than the plurality of storage devices; and

a processor that executes a process including

deleting the data that can be restored from the storage unit when data that belongs to data stored in a first storage device and which can be restored by using data and parity that are distributed and stored in another storage device that is in the power-on state is stored in the storage unit,

writing data that belongs to the data stored in the first storage device and which will not be restored even by using the data and parity that are distributed and stored in the other storage device that is in the power-on state to the storage unit,

switching the first storage device to the power-off state after writing the data that will not be restored to the storage unit, and

reading the data that has been stored in the storage unit and which will not be restored when a request to read the data that will not be restored is given when the first storage device is in the power-off state.

2. The distributed storage system according to claim 1, wherein

the process executed by the processor further including

acquiring the data that can be restored by using the data and parity that are distributed and stored in the other storage device that is in the power-on state when a request to read the data that can be restored is given when the first storage device is in the power-off state, and

the reading processing that is performed by the processor further includes processing to read the data acquired by the acquiring processing.

3. The distributed storage system according to claim 1, wherein

the writing processing that is performed by the processor further includes processing to write data having a high possibility of being used to the storage unit when writing the data that will not be restored to the storage unit.

4. The distributed storage system according to claim 1, wherein

the writing processing that is performed by the processor further includes processing to write the data that will not be restored to another storage device that is in the power-on state when a request to update the data that has been stored in the first storage device and which will not be restored is given when the first storage device is in the power-off state, and further includes processing to write data having a high possibility of being used from among the data stored in the storage device that is in the power-on state to the storage unit after the data that has been stored in the storage unit and which will not be restored is deleted,

the deletion processing that is performed by the processor further includes processing to delete the data before updating that has been stored in the storage unit and which will not be restored after the data that will not be restored is written to another storage device in the power-on state, and

the reading processing that is performed by the processor further includes processing to read the data that has been stored in the storage device and which will not be restored when a request to read the data that will not be restored is given when the first storage device is in the power-off state and the data that will not be restored has been written to the other storage device.

5. The distributed storage system according to claim 1, wherein

the process executed by the processor further including

acquiring the data that is identified by a data identifier stored in the storage device and which can be restored when a second storage device enters the power-on state when the first storage device is in the power-off state,

the writing processing that is performed by the processor further includes processing to write the data identifier of the data that can be restored to the storage unit after the data that can be restored is deleted from the storage unit by the deleting processing, to write the acquired data to the storage unit when the data that can be restored is acquired by the acquiring processing, and to write the parity stored in another storage device in the power-on state to the second storage device,

the switching processing that is performed by processor further includes processing to switch the second storage device to the power-off state after the parity stored in another storage device that is in the power-on state is written to the second storage device,

the deleting processing that is performed by the processor further includes processing to delete the parity stored in another storage device that is in the power-on state from the other storage device after the second storage device is switched to the power-off state, and

the reading processing that is performed by the processor further includes processing to read the data that has been stored in the storage unit and which can be restored when a request to read the data that has been acquired and which can be restored is given.

6. The distributed storage system according to claim 1, wherein

the deleting processing that is performed by the processor further includes processing to delete the data that will not be restored from the storage unit after the first storage device enters the power-on state, and

the writing processing that is performed by the processor further includes processing to write data having a high possibility of being used from among the data stored in the storage device that is in the power-on state to the storage unit.

7. The distributed storage system according to claim 5, wherein

the writing processing that is performed by the processor includes processing to write the parity and the data that will not be restored to an empty area of the other storage device that is in the power-on state, and

the switching processing that is performed by the processor includes processing to switch the second storage device to the power-on state when the empty area of the other storage device that is in the power-on state becomes lower than a predetermined amount.

8. The distributed storage system according to claim 1, wherein

the writing processing that is performed by the processor includes processing to write the parity and the data that will not be restored to the empty area of the other storage device that is in the power-on state and to write the data that has been stored in the other storage device that is in the power-on state and which will not be restored to the first storage device after the first storage device enters the power-on state,

the switching processing that is performed by the processor includes processing to switch the first storage device to the power-on state when the empty area of the other storage device that is in the power-on state becomes lower than a predetermined amount, and

the deleting processing that is performed by the processor includes processing to delete the data that has been stored in the other storage device that is in the power-on state and which will not be restored when the first storage device has entered the power-on state and when the data that will not be restored has been written to the first storage device.

9. The distributed storage system according to claim 1, wherein

the information processing device or the other information processing devices includes:

the storage unit or the processor or any combination thereof.

10. A storage device control method that is performed by a processor of an information processing device including a storage unit that is accessed more preferentially than a plurality of storage units connected so as to be capable of communication, the storage device control method comprising:

a process that is performed by the processor including

deleting the data that can be restored from the storage unit when data that belongs to data stored in a first storage device and which can be restored by using data and parity that are distributed and stored in another storage device that is in the power-on state is stored in the storage unit,

writing data that belongs to the data stored in the first storage device and which will not be restored even by using the data and parity that are distributed and stored in the other storage device that is in the power-on state to the storage unit;

switching the first storage device into the power-off state; and

reading the data that has been stored in the storage device and which will not be restored stored when a request to read the data that will not be restored is given when the first storage device is in the power-off state.

11. The storage device control method according to claim 10, wherein

the process that is performed by the processor further including

acquiring the data that can be restored by using data and parity that are distributed and stored in the other storage device that is in the power-on state when a request to read the data that can be restored is given when the first storage device is in the power-off state;

and

reading the acquired data.

12. The storage device control method according to claim 10, wherein

the process that is performed by the processor further including

writing data having a high possibility of being used to the storage unit in the processing to write the data that will not be restored to the storage unit.

13. A non-transitory computer-readable recording medium storing programs for causing a processor of an information processing device including a storage unit that is accessed more preferentially than a plurality of storage devices connected so as to be capable of communication, to perform storage device control process, the storage device control process comprising:

a process that is performed by the processor including

deleting the data that can be restored from the storage unit when data that belongs to data stored in a first storage device and which can be restored by using data and parity that are distributed and stored in another storage device that is in the power-on state is stored in the storage unit,

writing data that belongs to the data stored in the first storage device and which will not be restored by using the data and parity that are distributed and stored in the other storage device that is in the power-on state to the storage unit;

switching the first storage device into the power-off state; and

reading the data that has been stored in the storage unit and which will not be restored when a request to read the data that will not be restored is given when the first storage device is in the power-off state.

14. The non-transitory computer-readable recording medium according to claim 13, wherein

the process that is performed by the processor further including

acquiring the data that can be restored by using data and parity that are distributed and stored in another storage device that is in the power-on state when a request to read the data that can be restored is given in the state when the first storage device is in the power-off state;

and

reading the acquired data.

15. The non-transitory computer-readable recording medium according to claim 13, wherein

the process that is performed by the processor further including

writing data having a high possibility of being used to the storage unit in the processing to write the data that will not be restored to the storage unit.