STORAGE APPARATUS PROVIDED WITH A PLURALITY OF NONVOLATILE SEMICONDUCTOR STORAGE MEDIA AND STORAGE CONTROL METHOD

• US 20130205070A1
• Filed: 02/08/2012
• Published: 08/08/2013
• Est. Priority Date: 02/08/2012
• Status: Active Grant

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Koseki, Hideyuki, Ogawa, Junji
• Granted Patent: US 9,405,478 B2
• Time in Patent Office: Days
• US Class Current: 711/103
• CPC Class Codes: G06F 3/0605 by facilitating the interaction with a user or administrator
• CPC Class Codes: G06F 3/0608 Saving storage space on storage systems
• CPC Class Codes: G06F 3/0616 in relation to life time, e.g. increasing Mean Time Between Failures [MTBF]
• CPC Class Codes: G06F 3/0647 Migration mechanisms
• CPC Class Codes: G06F 3/0659 Command handling arrangements, e.g. command buffers, queues, command scheduling
• CPC Class Codes: G06F 3/0665 at area level, e.g. provisioning of virtual or logical volumes
• CPC Class Codes: G06F 3/067 Distributed or networked storage systems, e.g. storage area networks [SAN], network attached storage [NAS]
• CPC Class Codes: G06F 3/0688 Non-volatile semiconductor memory arrays

Abstract

A storage apparatus is provided with a plurality of nonvolatile semiconductor storage media and a storage controller that is a controller that is coupled to the plurality of semiconductor storage media. The storage controller identifies a first semiconductor storage unit that is at least one semiconductor storage media and a second semiconductor storage unit that is at least one semiconductor storage media and that is provided with a remaining length of life shorter than that of the first semiconductor storage unit based on the remaining life length information that has been acquired. The storage controller moreover identifies a first logical storage region for the first semiconductor storage unit and a second logical storage region that is provided with a write load higher than that of the first logical storage region for the second semiconductor storage unit based on the statistics information that indicates the statistics that is related to a write for every logical storage region. The storage controller reads data from the first logical storage region and the second logical storage region, and writes data that has been read from the first logical storage region to the second logical storage region and/or writes data that has been read from the second logical storage region to the first logical storage region.

Claims

1. A storage apparatus, comprising:

a plurality of nonvolatile semiconductor storage unit that is provided with a memory controller; and

a storage controller that is a controller that is coupled to the plurality of semiconductor storage unit,

wherein each of the semiconductor storage unit is configured by at least one nonvolatile semiconductor storage media and is a basis of a logical storage region,

the storage controller writes data to a semiconductor storage unit that is a basis of a logical storage region of a write destination of a plurality of logical storage regions,

the storage controller acquires the internal information from each of the semiconductor storage media on a regular basis or on an irregular basis for instance and stores the internal information that has been acquired for every semiconductor storage medium,

the storage controller stores the statistics information that indicates the statistics that is related to a write for every logical storage region and stores the remaining life length information that is the information that is related to a remaining length of life of each of the semiconductor storage media for every semiconductor storage medium,

(A) the storage controller identifies a first semiconductor storage unit and a second semiconductor storage unit that is provided with a remaining length of life shorter than that of the first semiconductor storage unit based on the remaining life length information that has been acquired,

(B) the storage controller moreover identifies a first logical storage region for the first semiconductor storage unit and a second logical storage region that is provided with a write load higher than that of the first logical storage region for the second semiconductor storage unit based on the statistics information that indicates the statistics that is related to a write for every logical storage region, and

(C) the storage controller reads data from the first logical storage region group and the second logical storage region, writes data that has been read from the first logical storage region to the second logical storage region, and/or writes data that has been read from the second logical storage region to the first logical storage region.

2. A storage apparatus according to claim 1, wherein:

the internal information for every semiconductor storage medium includes a numerical value that is related to a remaining length of life of the semiconductor storage medium as the remaining life length information and is the information in a unit larger than the minimum unit of a storage region that is included in the semiconductor storage medium, and

the storage controller predicts a remaining length of life of the semiconductor storage medium based on the numerical value in the internal information that has been acquired at a first point of time and the numerical value in the internal information that has been acquired at a second point of time before the first point of time for each of the semiconductor storage media.

3. A storage apparatus according to claim 2, wherein:

a write load for a logical storage region based on the semiconductor storage media is a load that conforms to a write amount that is a total amount of data that has been transmitted to the logical storage region as a write destination.

4. A storage apparatus according to claim 3, wherein:

a write load for the logical storage region is a load that is based on the write amount and a predicted write increase-decrease rate that is obtained based on the statistics information by the storage controller, and

the predicted write increase-decrease rate for the logical storage region is obtained based on the statistics that is related to a write to the logical storage region.

5. A storage apparatus according to claim 4, wherein:

the statistics that is related to a write to the logical storage region are an average size of data that conforms to a write to the logical storage region and/or whether a write destination of a write to the logical storage region is sequential or random.

6. A storage apparatus according to claim 2, wherein:

a plurality of RAID groups is formed by the plurality of semiconductor storage media,

the semiconductor storage unit is a RAID group,

at least two logical storage region groups are formed for every RAID group,

the logical storage region group is an aggregate of at least two logical storage regions that are corresponded to at least two semiconductor storage media that configure the RAID group,

in the (A), a first RAID group and a second RAID group that is provided with a remaining length of life that is shorter than that of the first RAID group are identified based on a remaining length of life of each semiconductor storage medium,

the first RAID group and the second RAID group are the first semiconductor storage unit and the second semiconductor storage unit, and in the (B), the first logical storage region group is a logical storage region group based on the first RAID group and the second logical storage region group is a logical storage region group based on the second RAID group.

7. A storage apparatus according to claim 6, wherein:

the storage controller executes the following (G) in the case in which the condition of the following (F) is satisfied;

(F) for at least one of the first RAID group and the second RAID group, at least two semiconductor storage media based on the logical storage region group to which data has been written in the (C) varies in a remaining length of life and at least two logical storage regions that configure the logical storage region group varies in a write load; and

(G) data is exchanged between a first logical storage region and a second logical storage region for the same logical storage region group based on a write load of the at least two logical storage regions and a remaining length of life of at least two semiconductor storage media based on the logical storage region to which data has been written in the (C),

the first logical storage region is based on the first semiconductor storage medium of at least two semiconductor storage media,

the second logical storage region is based on the second semiconductor storage medium of at least two semiconductor storage media,

the second semiconductor storage medium is a semiconductor storage medium that is provided with a remaining length of life that is shorter than that of the first semiconductor storage medium, and

the second logical storage region is a logical storage region that is provided with a write load that is higher than that of the first logical storage region.

8. A storage apparatus according to claim 7, wherein:

each logical storage region is configured by a plurality of stripe lines, and

in the case in which the (G) is executed and at least two data that are stored into the same stripe line are stored into the same semiconductor storage medium, the (G) is not executed even if the condition of the (F) is satisfied.

9. A storage apparatus according to claim 1, wherein:

a plurality of RAID groups is formed by the plurality of semiconductor storage media,

at least two logical storage region groups are formed for every RAID group,

in the (A), a first semiconductor storage medium in a first RAID group and a second semiconductor storage medium in a second RAID group that is provided with a remaining length of life that is shorter than that of the first RAID group are identified based on a remaining length of life of each semiconductor storage medium,

the first semiconductor storage medium and the second semiconductor storage medium are the first semiconductor storage unit and the second semiconductor storage unit, and

in the (B), the first logical storage region is a logical storage region based on the first semiconductor storage medium and the second logical storage region is a logical storage region based on the second semiconductor storage medium.

10. A storage apparatus according to claim 9, wherein:

the storage controller provides a virtual volume that is configured by a plurality of virtual regions, allocates a logical storage region group to a virtual region of a write destination, and writes data of a write target to the logical storage region group, and

in the (C), the second logical storage region is allocated to a first virtual region to which a logical storage region group based on the first RAID group has been allocated as substitute for the first storage region of the logical storage region group, and/or the first logical storage region is allocated to a second virtual region to which a logical storage region group based on the second RAID group has been allocated as substitute for the second storage region of the logical storage region group.

11. A storage apparatus according to claim 2, wherein:

a RAID groups is formed by the plurality of semiconductor storage media,

at least two logical storage regions are formed based on the RAID group,

in the (A), a first semiconductor storage medium and a second semiconductor storage medium that are included in a first RAID group are identified based on a remaining length of life of each semiconductor storage medium,

the first semiconductor storage medium and the second semiconductor storage medium are the first semiconductor storage unit and the second semiconductor storage unit, and

in the (B), the first logical storage region is a logical storage region based on the first semiconductor storage medium and the second logical storage region is a logical storage region based on the second semiconductor storage medium.

12. A storage apparatus according to claim 11, wherein:

each logical storage region group is configured by a plurality of stripe lines, and

in the case in which at least two data that are stored into the same stripe line are stored into the same semiconductor storage medium, the (C) is not executed.

13. A storage apparatus according to claim 1, wherein:

the logical storage region of a write destination of data that has been read in the (C) is decided based on a read load of the logical storage region in addition to the write load for the logical storage region, and a read load that conforms to an amount of data that is read in a unit time.

14. A storage apparatus according to claim 2, wherein:

the storage controller stores the information that indicates a period of guarantee of the semiconductor storage media, and

the first semiconductor storage unit and the second semiconductor storage unit

the characteristic is a remaining length of life and a period of guarantee are decided based on a result of a comparison of a remaining length of life of each semiconductor storage unit and a period of guarantee of each semiconductor storage unit.

15. A storage apparatus according to claim 2, wherein:

the numerical value is a numerical value that is related to at least one of a remaining frequency of erasing and a real write amount, and

the real write amount of a semiconductor storage unit is a total amount of data that has been written in the semiconductor storage unit as a practical matter.

16. A storage apparatus according to claim 2, wherein:

a unit of the predicted remaining length of life is a day.

17. A storage apparatus according to claim 2, wherein:

(A) the storage controller identifies a semiconductor storage unit in which a remaining length of life is equal to or less than a threshold value based on the remaining life length information that has been acquired,

(B) the storage controller identifies a first logical storage region for the identified semiconductor storage unit and a second logical storage region that is provided with a write load higher than that of the first logical storage region based on the statistics information that is related to a write for every logical storage region, and

(C) the storage controller reads data from the first logical storage region group and the second logical storage region, writes data that has been read from the first logical storage region to the second logical storage region, and/or writes data that has been read from the second logical storage region to the first logical storage region.

18. A storage control method comprising the steps of:

identifying a first semiconductor storage unit that is a semiconductor storage medium and a second semiconductor storage unit that is at least one semiconductor storage medium and that is provided with a remaining length of life shorter than that of the first semiconductor storage unit based on the remaining life length information that is the information that is related to a remaining length of life of each non-volatile semiconductor storage medium,

identifying a first logical storage region for the first semiconductor storage unit and a second logical storage region that is provided with a write load higher than that of the first logical storage region for the second semiconductor storage medium based on the statistics information that indicates the statistics that is related to a write of a plurality of semiconductor storage regions based on a plurality of semiconductor storage units, and

reading data from the first logical storage region group and the second logical storage region, writing data that has been read from the first logical storage region to the second logical storage region, and/or

writing data that has been read from the second logical storage region to the first logical storage region.