METHODS, APPARATUSES AND COMPUTER PROGRAM PRODUCTS FOR REALLOCATING RESOURCE IN A DISK SYSTEM

• US 20200133535A1
• Filed: 09/19/2019
• Published: 04/30/2020
• Est. Priority Date: 10/31/2018
• Status: Active Grant

• Current Assignee: Emc IP Holding Company LLC (Dell Technologies Inc.)
• Original Assignee: Emc IP Holding Company LLC (Dell Technologies Inc.)
• Inventors: Ma, Chun, Gong, Shaoqin, Tang, Haiying, Sun, Tianshu, Qiu, Zhihui
• Granted Patent: US 11,320,996 B2
• Time in Patent Office: Days
• CPC Class Codes: G06F 11/1076 Parity data used in redundant arrays of independent storages, e.g. in RAID systems
• CPC Class Codes: G06F 17/11 for solving equations , e.g. nonlinear equations, general mathematical optimization problems optimization specially adapted for a specific administrative, business or logistic context G06Q10/04
• CPC Class Codes: G06F 3/0604 Improving or facilitating administration, e.g. storage management
• CPC Class Codes: G06F 3/0616 in relation to life time, e.g. increasing Mean Time Between Failures [MTBF]
• CPC Class Codes: G06F 3/0631 by allocating resources to storage systems
• CPC Class Codes: G06F 3/0647 Migration mechanisms
• CPC Class Codes: G06F 3/0674 Disk device
• CPC Class Codes: G06F 3/0689 Disk arrays, e.g. RAID, JBOD
• CPC Class Codes: G11B 20/10 Digital recording or reproducing
• CPC Class Codes: G11B 20/1217 on discs

Abstract

Techniques perform resource reallocation for a disk system. Such techniques involve: determining, based on conditions of allocated disk extents in a plurality of disks and wear levels of the plurality of disks, an enhanced neighbor matrix characterizing both distribution evenness of the disk extents on the plurality of disks and the wear levels of the plurality of disks; and performing a resource reallocation operation on the plurality of disks based on the enhanced neighbor matrix. Accordingly, it is possible to, through the enhanced neighbor matrix that is based on the wear level, simultaneously consider both the distribution evenness of disk extents and the wear level of the disk while performing resource reallocation, thereby avoiding the problem of ping-pang resource reallocation caused by inconsistent standards between different resource reallocation methods, and having good compatibility with existing storage systems.

Claims

1. A method for performing resource reallocation for a disk system, comprising:

determining, based on conditions of allocated disk extents in a plurality of disks and wear levels of the plurality of disks, an enhanced neighbor matrix characterizing both distribution evenness of the disk extents on the plurality of disks and the wear levels of the plurality of disks; and

performing a resource reallocation operation on the plurality of disks based on the enhanced neighbor matrix.

2. The method of claim 1, wherein the determining the enhanced neighbor matrix comprises:

determining respective elements of the enhanced neighbor matrix by adjusting respective elements of an original neighbor matrix using a weight value,

wherein the original neighbor matrix characterizes evenness of distribution of the disk extents on the plurality of disks, and

wherein the weight value is determined based on an ideal wear level of the plurality of disks and respective wear levels of respective disk pairs corresponding to respective elements of the original neighbor matrix.

3. The method of claim 2, wherein the weight value is determined as:

4. The method of claim 3, wherein the performing resource reallocation operation on the plurality of disks based on the enhanced neighbor matrix comprises:

determining a disk pair corresponding to a maximum value of elements in the enhanced neighbor matrix; and

performing resource reallocation by taking one disk in the disk pair as a source disk, based on the load level of the disk pair.

5. The method of claim 4, wherein the load level is divided into a predetermined tolerance area, a hot disk area above the predetermined tolerance area, and a cold disk area below the predetermined tolerance area,

wherein the predetermined tolerance area is further divided into a warm disk area above a predetermined load level and a cool disk area below the predetermined load level, and

wherein the resource reallocation is performed based on which one or ones of the hot disk area, the cold disk area, the warm disk area and the cool disk area the load levels of two disks in the disk pair are located in.

6. The method of claim 5, wherein the determining the disk pair corresponding to a maximum value of elements in the enhanced neighbor matrix comprises:

in a case where there are a plurality of disk pairs corresponding to the maximum value, determining the disk pair according to the following priority;

a disk pair including a disk with a load level in the hot disk area;

a disk pair including a disk with a load level in the cold disk area; and

a disk pair including a disk with the highest load level.

7. The method of claim 5, wherein the performing resource reallocation on one disk in the disk pair based on the load level of the disk pair comprises:

in response to determining that the load level of at least one disk in the disk pair is in the hot disk area,

determining a disk with a higher load level in the disk pair as a source disk,

taking, among other disks than the disk pair, a disk with the lowest load level as a target disk,

determining a source disk extent in the source disk, the source disk extent being a disk extent with the highest load level among disk extents which are neighboring to a disk with a lower load level in the disk pair but not neighboring to the target disk; and

performing resource reallocation on the source disk extent and the target disk.

8. The method of claim 5, wherein the performing resource reallocation on one disk in the disk pair based on the load level of the disk pair comprises:

in response to determining that the load level of at least one disk in the disk pairs is in the cold disk area,

determining a disk with a lower load level in the disk pair as a source disk,

taking, among other disks than the disk pair, a disk with the highest load level as a target disk,

determining a source disk extent in the source disk, the source disk extent being a disk extent with the lowest load level among disk extents which are neighboring to a disk with a higher load level in the disk pair but not neighboring to the target disk;

determining a target disk extent in the target disk, the target disk extent being a disk extent with the highest load level among disk extents which are not neighboring to either disk in the disk pair; and

performing resource reallocation on the source disk extent and the target disk.

9. The method of claim 4, wherein the performing resource reallocation on one disk in the disk pair based on the load level of the disk pair comprises:

in response to determining that the load level of at least one disk in the disk pair is in the warm disk area,

determining a disk with a higher load level in the disk pair as a source disk,

taking, among other disks than the disk pair, a disk with the lowest load level as a target disk,

determining a source disk extent in the source disk, the source disk extent being a disk extent with the highest load level among disk extents which are neighboring to a disk with a lower load level in the disk pair but not neighboring to the target disk; and

performing resource reallocation on the source disk extent and the target disk.

10. The method of claim 4, wherein the performing resource reallocation on one disk in the disk pair based on the load level of the disk pair comprises:

in response to determining that the load level of at least one disk in the disk pairs is in the cool disk area,

determining a disk with a lower load level in the disk pair as a source disk,

taking, among other disks than the disk pair, a disk with the highest load level as a target disk,

determining a source disk extent in the source disk, wherein the source disk extent is a disk extent with the lowest load level among disk extents which are neighboring to a disk with a higher load level in the disk pair but not neighboring to the target disk;

determining a target disk extent in the target disk, wherein the target disk extent is a disk extent with the highest load level among disk extents which are not neighboring to either disk in the disk pair; and

performing resource reallocation on the source disk extent and the target disk.

11. The method of claim 10, wherein the source disk is determined according to the following priority:

a disk with a load level in the hot disk area and with a higher load level in the disk pair, or a disk with a load level in the cold disk area and with the lower load level in the disk pair;

a disk with a load level in the warm disk area and with a higher load level in the disk pair; and

a disk with a load level in the cool disk area and with a lower load level in the disk pair.

12. An apparatus for performing resource reallocation on a disk system, comprising:

a processor; and

a memory coupled to the processor, the memory having instructions stored therein, which, when executed by the processor, causes the apparatus to;

determine, based on conditions of allocated disk extents in a plurality of disks and wear levels of the plurality of disks, an enhanced neighbor matrix characterizing both distribution evenness of the disk extents on the plurality of disks and the wear levels of the plurality of disks; and

performing a resource reallocation operation on the plurality of disks based on the enhanced neighbor matrix.

13. The apparatus according to claim 12, wherein the determining the enhanced neighbor matrix comprises:

determining respective elements of the enhanced neighbor matrix by adjusting respective elements of an original neighbor matrix using a weight value,

wherein the original neighbor matrix characterizes evenness of distribution of the disk extents on the plurality of disks, and

wherein the weight value is determined based on an ideal wear level of the plurality of disks and respective wear levels of respective disk pairs corresponding to respective elements of the original neighbor matrix.

14. The apparatus according to claim 13, wherein the weight value is determined as:

15. The apparatus of claim 14, wherein the performing resource reallocation operation on the plurality of disks based on the enhanced neighbor matrix comprises:

determining a disk pair corresponding to a maximum value of elements in the enhanced neighbor matrix; and

performing resource reallocation by taking one disk in the disk pair as a source disk, based on the load level of the disk pair.

16. The apparatus of claim 15, wherein the load level is divided into a predetermined tolerance area, a hot disk area above the predetermined tolerance area, and a cold disk area below the predetermined tolerance area,

wherein the predetermined tolerance area is further divided into a warm disk area above a predetermined load level and a cool disk area below the predetermined load level, and

wherein performing the resource reallocation is determined based on which one or ores of the hot disk area, the cold disk area, the warm disk area and the cool disk area the load levels of two disks in the disk pair are located in.

17. The apparatus of claim 15, wherein the determining the disk pair corresponding to a maximum value of elements in the enhanced neighbor matrix comprises:

in a case where there are a plurality of disk pairs corresponding to the maximum value, determining the disk pair according to the following priority;

a disk pair including a disk with a load level in the hot disk area;

a disk pair including a disk with a load level in the cold disk area; and

a disk pair including a disk with the highest load level.

18. The apparatus of claim 16, wherein the performing resource reallocation on one disk in the disk pair based on the load level of the disk pair comprises:

in response to determining that the load level of at least one disk in the disk pair is in the hot disk area,

determining a disk with a higher load level in the disk pair as a source disk,

taking, among other disks than the disk pair, a disk with the lowest load level as a target disk,

determining a source disk extent in the source disk, the source disk extent being a disk extent with the highest load level among disk extents which are neighboring to a disk with a lower load level in the disk pair but not neighboring to the target disk; and

performing resource reallocation on the source disk extent and the target disk.

19. The apparatus of claim 16, wherein the performing resource reallocation on one disk in the disk pair based on the load level of the disk pair comprises:

in response to determining that the load level of at least one disk in the disk pairs is in the cold disk area,

determining a disk with a lower load level in the disk pair as a source disk,

taking, among other disks than the disk pair, a disk with the highest load level as a target disk,

determining a source disk extent in the source disk, the source disk extent being a disk extent with the lowest load level among disk extents which are neighboring to a disk with a higher load level in the disk pair but not neighboring to the target disk;

determining a target disk extent in the target disk, the target disk extent being a disk extent with the highest load level among disk extents which are not neighboring to either disk in the disk pair; and

performing resource reallocation on the source disk extent and the target disk.

20. The apparatus of claim 16, wherein the performing resource reallocation on one disk in the disk pair based on the load level of the disk pair comprises:

in response to determining that the load level of at least one disk in the disk pair is in the warm disk area,

determining a disk with a higher load level in the disk pair as a source disk,

taking, among other disks than the disk pair, a disk with the lowest load level as a target disk,

determining a source disk extent in the source disk, the source disk extent being a disk extent with the highest load level among disk extents which are neighboring to a disk with a lower load level in the disk pair but not neighboring to the target disk; and

performing resource reallocation on the source disk extent and the target disk.

21. The apparatus of claim 16, wherein the performing resource reallocation on one disk in the disk pair based on the load level of the disk pair comprises:

in response to determining that the load level of at least one disk in the disk pairs is in the cool disk area,

determining a disk with a lower load level in the disk pair as a source disk,

taking, among other disks than the disk pair, a disk with the highest load level as a target disk,

determining a source disk extent in the source disk, wherein the source disk extent is a disk extent with the lowest load level among disk extents which are neighboring to a disk with a higher load level in the disk pair but not neighboring to the target disk;

determining a target disk extent in the target disk, wherein the target disk extent is a disk extent with the highest load level among disk extents which are not neighboring to either disk in the disk pair; and

performing resource reallocation on the source disk extent and the target disk.

22. The apparatus of claim 21, wherein the source disk is determined according to the following priority:

a disk with a load level in the hot disk area and with a higher load level in the disk pair, or a disk with a load level in the cold disk area and with the lowest load level in the disk pair;

a disk with a load level in the warm disk area and with a higher load level in the disk pair; and

a disk with a load level in the cool disk area and with a lower load level in the disk pair.

23. A computer program product having a non-transitory computer readable medium which stores a set of instructions to perform resource reallocation for a disk system;

the set of instructions, when carried out by computerized circuitry, causing the computerized circuitry to perform a method of;

determining, based on conditions of allocated disk extents in a plurality of disks and wear levels of the plurality of disks, an enhanced neighbor matrix characterizing both distribution evenness of the disk extents on the plurality of disks and the wear levels of the plurality of disks; and

performing a resource reallocation operation on the plurality of disks based on the enhanced neighbor matrix.