Storage system
AssigneeHitachi, Ltd.
InventorsMitsuo Hayasaka, Ken Nomura, Keiichi Matsuzawa, Hitoshi Kamei
Life of this patent
Estimating the term…
Abstract
An example of storage system obtains a reference request of a reference request data block that is included in the content and is stored in the medium area. The storage system determines a number of gaps among addresses, in the medium area, of a plurality of data blocks continuous in the content including the reference request data block. The storage system determines, based on the number of gaps, whether or not defrag based on the plurality of data blocks is valid. The storage system writes, when the defrag is determined to be valid, the plurality of data blocks read from the medium area to the memory area, into continuous address areas of the medium area.
Claims11
A storage system, comprising:
- a medium area provided by at least one storage device to store data of a content;
- and
- a controller comprising a memory area for temporarily storing data of the medium area,
- wherein the controller is configured to:
- obtain, from a source, a reference request of a reference request data block that is included in the content and is stored in the medium area;
- read, from the medium area, k data blocks, wherein k is a number larger than the requested reference request data block and is a value predetermined before the reference request;
- determine an occupation range in content and a number of gaps among addresses, in the medium area, of a plurality of data blocks continuous in the content including the reference request data block;
- determine, based on the occupation range in content and the number of gaps, whether or not defrag based on the plurality of data blocks is valid;
- write, when the defrag is determined to be valid, the plurality of data blocks read from the medium area to the memory area, into continuous address areas of the medium area;
- and
- send the reference request data block to the source,
- wherein the number of gaps needed for defragment in case of the occupation range in content includes head data or tail end data of the content is fewer than the number of gaps needed for defragment in case of the occupation range in content does not include head data or tail end data of the content.
A method of controlling a storage system,
- the storage system comprising:
- a medium area provided by at least one storage device to store data of a content;
- and
- a memory area for temporarily storing data of the medium area,
- the method comprising:
- obtaining, from a source, a reference request of a reference request data block that is included in the content and is stored in the medium area;
- reading, from the medium area, k data blocks, wherein k is a number larger than the requested reference request data block and is a value predetermined before the reference request;
- determining an occupation range in content and a number of gaps among addresses, in the medium area, of a plurality of data blocks continuous in the content including the reference request data block;
- determining, based on the occupation range in content and the number of gaps, whether or not defrag based on the plurality of data blocks is valid;
- writing, when the defrag is determined to be valid, the plurality of data blocks stored in the medium area into continuous address areas of the medium area;
- and
- sending the reference request data block to the source,
- wherein the number of gaps needed for defragment in case of the occupation range in content includes head data or tail end data of the content is fewer than the number of gaps needed for defragment in case of the occupation range in content does not include head data or tail end data of the content.
Dependencies are inferred from the claim text.