Data migration method, data migration apparatus, and storage device

Patent metadata

Field	Value
Publication number	US-9733844-B2
Application number	US-201514662928-A
Country	US
Kind code	B2
Filing date	Mar 19, 2015
Priority date	Sep 24, 2013
Publication date	Aug 15, 2017
Grant date	Aug 15, 2017

Abstract

A method for extending life of a storage system, wherein a storage controller determines a source solid-state disk (SSD) in a disk group with a capacity usage ratio greater than an average capacity usage ratio of the disk group. The capacity usage ratio of the source SSD is a ratio of a used capacity of the source SSD to an available capacity of the source SSD. The storage controller selects at least one destination SSD in the disk group with a capacity usage ratio less than the average capacity usage ratio of the disk group. And then the storage controller calculates an amount of data to be migrated from the source SSD, based on the capacity usage ratio of the source SSD and the average capacity usage ratio. At last, the storage controller migrates the data to be migrated from the source SSD to the one or more destination SSDs.

First claim

What is claimed is:

1. A method for extending life of a storage system which includes a storage controller and a disk group, wherein the disk group includes a plurality of solid-state disks (SSDs), wherein each of the SSDs is divided into multiple chunks that are accessible to the storage controller, the method performed by the storage controller comprising:
monitoring a bad blocks capacity of each of the plurality of SSDs, wherein each SSD includes multiple blocks, and wherein at least one SSD includes one or more bad blocks;
selecting the at least one SSD as a source SSD in response to the bad blocks capacity of one of the SSDs reaching a threshold;
calculating an amount of data to be migrated from the source SSD based on a capacity usage ratio of the source SSD and an average capacity usage ratio of the disk group, wherein the capacity usage ratio of the source SSD is greater than the average capacity usage ratio of the disk group, wherein the capacity usage ratio of the source SSD is a ratio of an occupied capacity of the source SSD divided by an available capacity of the source SSD, wherein the average capacity usage ratio of the disk group is a ratio of an occupied capacity of the disk group divided by an available capacity of the disk group;
identifying a number of chunks to be migrated from the source SSD based on the amount of data to be migrated from the source SSD and a size of each chunk;
selecting one or more destination SSDs in the disk group with a capacity usage ratio less than the average capacity usage ratio of the disk group; and
migrating the data to be migrated from the source SSD to the one or more destination SSDs according to the number of chunks,
wherein the data to be migrated from the source SSD is migrated in a unit of chunk,
wherein each of multiple chunks is unit of a chunk group, and
wherein the chunk group includes a plurality of chunks each belonging to different SSDs.

2. The method according to claim 1 , wherein migrating the data comprises:
calculating, based on a capacity usage ratio of each destination SSD and the average capacity usage ratio of the disk group, an amount of data allowed to be migrated to each destination SSD; and
migrating the amount of data allowed to be migrated to each destination SSD, wherein the amount of data allowed to be migrated to each destination SSD is at least a portion of the data to be migrated from the source SSD.

3. The method according to claim 2 , wherein calculating, based on the capacity usage ratio of each destination SSD and the average capacity usage ratio of the disk group, the amount of data allowed to be migrated to each destination SSD comprises:
obtaining a difference value between the capacity usage ratio of each destination SSD and the average capacity usage ratio of the disk group; and
obtaining the amount of data allowed to be migrated to each destination SSD by multiplying the difference value between the capacity usage ratio of each destination SSD and the average capacity usage ratio of the disk group by an available capacity of the destination SSD.

4. The method according to claim 1 , wherein calculating the amount of data to be migrated from the source SSD based on the capacity usage ratio of the source SSD and the average capacity usage ratio comprises:
obtaining a difference value between the capacity usage ratio of the source SSD and the average capacity usage ratio of the disk group; and
obtaining the amount of data to be migrated from the source SSD by multiplying the difference value between the capacity usage ratio of the source SSD and the average capacity usage ratio of the disk group by the available capacity of the source SSD.

5. The method according to claim 1 , wherein the amount of data to be migrated from the source SSD is calculated based on the capacity usage ratio of the source SSD and the average capacity usage ratio in order to reduce a difference between the capacity usage ratio of the source SSD and the average capacity usage ratio of the disk group.

6. A storage system for storing data with optimized data distribution among solid-state disks (SSDs), the storage system comprising:
a processor; and
a plurality of SSDs for storing data, wherein each of the SSDs is divided into multiple chunks that are accessible to a processor,
wherein the processor is connected to the SSDs and is configured to:
monitor a bad blocks capacity of each of the plurality of SSDs, wherein each SSD includes multiple blocks, and wherein at least one SSD includes one or more bad blocks;
selecting the at least one SSD as a source SSD in response to the bad blocks capacity of one of the SSDs reaching a threshold;
calculate an amount of data to be migrated from the source SSD based on a capacity usage ratio of the source SSD and an average capacity usage ratio of the disk group, wherein the capacity usage ratio of the source SSD is greater than the average capacity usage ratio of the disk group, wherein the capacity usage ratio of the source SSD is a ratio of an occupied capacity of the source SSD divided by an available capacity of the source SSD, wherein the average capacity usage ratio of the disk group is a ratio of an occupied capacity of the disk group divided by an available capacity of the disk group;
identify a number of chunks to he migrated from the source SSD based on the amount of data to be migrated from the source SSD and a size of each chunk;
select one or more destination SSDs in the disk group with a capacity usage ratio less than the average capacity usage ratio of the disk group; and
migrate the data to he migrated from the source SSD to the one or more destination SSDs according to the number of chunks,

wherein the data to be migrated from the source SSD is migrated in a unit of chunk,
wherein each of multiple chunks is a unit of a chunk group, and
wherein the chunk group includes a plurality of chunks each belonging to different SSDs.

7. The storage system according to claim 6 , wherein the processor is further configured to:
calculate, based on a capacity usage ratio of each destination SSD and the average capacity usage ratio of the disk group, an amount of data allowed to be migrated to each destination SSD; and
migrate the amount of data allowed to be migrated to each destination SSD, wherein the amount of data allowed to be migrated to each destination SSD is at least a portion of the data to be migrated from the source SSD.

8. The storage system according to claim 7 , wherein the processor is further configured to:
obtain a difference value between the capacity usage ratio of each destination SSD and the average capacity usage ratio of the disk group; and
obtain the amount of data allowed to be migrated to each destination SSD by multiplying the difference value between the capacity usage ratio of each destination SSD and the average capacity usage ratio of the disk group by an available capacity of each destination SSD.

9. The storage system according to claim 6 , wherein the processor is further configured to:
obtain a difference value between the capacity usage ratio of the source SSD and the average capacity usage ratio of the disk group; and
obtain the amount of data to be migrated from the source SSD by multiplying the difference value between the capacity usage ratio of the source SSD and the average capacity usage ratio of the disk group by the available capacity of the source SSD.

10. The storage system according to claim 6 , wherein the amount of data. to be migrated from the source SSD is calculated based on the capacity usage ratio of the source SSD and the average capacity usage ratio in order to reduce a difference between the capacity usage ratio of the

Assignees

• Huawei Tech Co Ltd

Inventors

• Gong Tao
• Han Kun
• Wu Liming

Classifications

• G06F2212/7204

  Capacity control, e.g. partitioning, end-of-life degradation · CPC title

• G06F3/0608

  Saving storage space on storage systems · CPC title

• G06F3/0647

  Migration mechanisms · CPC title

• G06F3/0616 Primary

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

• G06F2212/7211

  Wear leveling · CPC title