Storage apparatus and storage control method

Patent metadata

Field	Value
Publication number	US-2016196075-A1
Application number	US-201314777555-A
Country	US
Kind code	A1
Filing date	Jul 19, 2013
Priority date	Jul 19, 2013
Publication date	Jul 7, 2016
Grant date	—

Abstract

A storage apparatus includes a semiconductor storage device, and a storage controller coupled to the semiconductor storage device, and which stores data to a logical storage area provided by the semiconductor storage device. The semiconductor storage device includes one or more non-volatile semiconductor storage media, and a medium controller coupled to the semiconductor storage media. The medium controller compresses data stored in the logical storage area, and stores the compressed data in the semiconductor storage medium. The size of a logical address space of the logical storage area is larger than a total of the sizes of physical address spaces of the semiconductor storage media.

First claim

1 . A storage apparatus comprising:
a semiconductor storage device including one or more non-volatile semiconductor storage media and a medium controller coupled to the semiconductor storage media; and a storage controller coupled to the semiconductor storage device and configured to store data to a logical storage area provided by the semiconductor storage device, the medium controller being configured to compress the data stored in the logical storage area, and store the compressed data to the semiconductor storage medium, and a size of a logical address space of the logical storage area being larger than a total of sizes of physical address spaces of the semiconductor storage media.

2 . The storage apparatus according to claim 1 , comprising:
a plurality of semiconductor storage units, each of the semiconductor storage units which comprises one or more semiconductor storage devices, wherein the storage controller is configured to
acquire exhaustion-related information for calculating a risk of exhaustion of a capacity of the semiconductor storage unit, from each of the plurality of semiconductor storage devices,
calculate a capacity exhaustion risk that is a risk of exhaustion of a capacity of the semiconductor storage unit, based on the acquired exhaustion-related information, for each of the plurality of semiconductor storage units, and
execute exhaustion avoidance processing of migrating data between semiconductor storage units to decrease the capacity exhaustion risk of any of the plurality of semiconductor storage units, based on the capacity exhaustion risk of each of the plurality of semiconductor storage units.

3 . The storage apparatus according to claim 2 , wherein
the storage controller is configured to
acquire remaining life information for calculating a remaining life of the semiconductor storage unit, from each of the plurality of semiconductor storage devices,
calculate the remaining life of the semiconductor storage unit, based on the acquired remaining life information, for each of the plurality of semiconductor storage units, and
execute life leveling processing of migrating data between the semiconductor storage units to level the remaining lives in the plurality of semiconductor storage units, based on the acquired remaining life information, for each of the plurality of semiconductor storage units, after the exhaustion avoidance processing is terminated.

4 . The storage apparatus according to claim 3 , wherein
the storage controller is configured to
acquire input/output amount information related to a data amount input/output to/from the semiconductor storage unit, from each of the plurality of semiconductor storage devices, and
execute input/output leveling processing of migrating data between the semiconductor storage units to level the input/output data amount about the plurality of semiconductor storage units, based on the acquired input/output amount information, for each of the plurality of semiconductor storage units, after the life leveling processing is terminated.

5 . The storage apparatus according to claim 2 , wherein
the storage controller is configured to execute the exhaustion avoidance processing, when the capacity exhaustion risk of any of the plurality of semiconductor storage units is equal to or larger than a predetermined threshold.

6 . The storage apparatus according to claim 2 , wherein
the exhaustion-related information includes a write amount, a compression ratio, and a free physical capacity, about the semiconductor storage device of an acquisition source of the exhaustion-related information, and the storage controller is configured to calculate the capacity exhaustion risk about the semiconductor storage device of the acquisition source of the exhaustion-related information and the semiconductor storage unit, based on the write amount, the compression ratio, and the free physical capacity included in the exhaustion-related information.

7 . The storage apparatus according to claim 2 , wherein
each of the semiconductor storage media comprises a plurality of blocks, and data is migrated in units of storage area larger than the block in the exhaustion avoidance processing.

8 . The storage apparatus according to claim 3 , wherein
the storage controller is configured to execute the life leveling processing, when there are two semiconductor storage units in which a difference in the remaining life between the two semiconductor storage units becomes equal to or larger than a predetermined threshold, in the plurality of semiconductor storage units.

9 . The storage apparatus according to claim 3 , wherein
the remaining life information includes a history of a remaining number of times of deletion that is the number of times by which deletion of data is possible, about the semiconductor storage device of the acquisition source of the remaining life information, and the storage controller is configured to calculate the remaining life of the semiconductor storage unit, based on the history of the remaining number of times of deletion, for each of the plurality of semiconductor storage units.

10 . The storage apparatus according to claim 3 , wherein,
in the life leveling processing,
when a first write expected amount in a first partial storage area having a large write expected amount in the semiconductor storage unit having a short remaining life is larger than a second write expected amount of a second partial storage area having a small write expected amount in the semiconductor storage unit having a long remaining life, the storage controller is configured to perform control to exchange data in the first partial storage area and data in the second partial storage area, and
when the first write expected amount is not larger than the second write expected amount, the storage controller is configured to perform control not to exchange the data in the first partial storage area and the data in the second partial storage area.

11 . The storage apparatus according to claim 4 , wherein
the storage controller is configured to execute the input/output leveling processing, when there are two semiconductor storage units in which a difference in the data amount input/output during a predetermined time becomes equal to or larger than a predetermined threshold, in the plurality of semiconductor storage units.

12 . The storage apparatus according to claim 1 , comprising:
a plurality of semiconductor storage units, each of the semiconductor storage units which comprises one or more semiconductor storage devices, wherein the storage controller is configured to
determine, before performing target data arrangement control processing, of a plurality of types of data arrangement control processing, whether a condition to be satisfied in the data arrangement control processing having higher priority than the target data arrangement control processing remains satisfied, even if the target data arrangement control processing is performed, and
perform the target data arrangement control processing, when a result of the determination is affirmative, and
each of the plurality of types of data arrangement control processing is processing in which data is migrated between the semiconductor storage units.

13 . The storage apparatus according to claim 12 , wherein
the plurality of types of data arrangement control processing includes at least two of exhaustion avoidance processing of migrating data between the semiconductor storage units to decrease a capacity exhaustion risk of any of the plurality of semiconductor storage units, life leveling processing of migrating data between the

Assignees

• Hitachi Ltd

Inventors

• Matsushita Takaki

Classifications

• G06F3/0655

  Vertical data movement, i.e. input-output transfer; data movement between one or more hosts and one or more storage devices · CPC title

• G06F3/0688

  Non-volatile semiconductor memory arrays · CPC title

• G06F3/0616 Primary

  in relation to life time, e.g. increasing Mean Time Between Failures [MTBF] · CPC title

• G06F12/0246

  in block erasable memory, e.g. flash memory · CPC title

• G06F2212/7201

  Logical to physical mapping or translation of blocks or pages · CPC title