Methods, apparatuses and computer program products for reallocating resource in a disk system

Patent metadata

Field	Value
Publication number	US-11320996-B2
Application number	US-201916575475-A
Country	US
Kind code	B2
Filing date	Sep 19, 2019
Priority date	Oct 31, 2018
Publication date	May 3, 2022
Grant date	May 3, 2022

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.

First claim

We claim:

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;

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,
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, and
wherein the weight value is determined as:
(1+α i /D _ WT ideal)*(1+α j /D _ WT ideal)

where

α
n

=

α
⁢

⁢
n

=

{

0
,

if
⁢

⁢

D_WT
n

<

D_WT
ideal

f
⁡

(

D_WT
n

-

D_WT
ideal

)

,

n
=
i

,
j

i and j respectively indicate numbers of disks of respective disk pairs corresponding to respective elements of the original neighbor matrix;
D_WT ideal indicates the ideal wear level of the plurality of disks;
D_WT n indicates an ideal wear level of disk n; and
f(x) is a monotonously increasing function, and f(0)=0.

2. The method of claim 1 , 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.

3. The method of claim 2 , 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.

4. The method of claim 3 , 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.

5. The method of claim 3 , 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.

6. The method of claim 3 , 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.

7. The method of claim 2 , 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 wit

Assignees

• Emc Ip Holding Co Llc

Inventors

• Ma Chun
• Gong Shaoqin
• Tang Haiying
• Sun Tianshu
• Qiu Zhihui

Classifications

• G06F3/0647

  Migration mechanisms · CPC title

• G06F3/0674

  Disk device · CPC title

• G06F3/0604

  Improving or facilitating administration, e.g. storage management · CPC title

• G06F17/11

  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 title

• G06F3/0689 Primary

  Disk arrays, e.g. RAID, JBOD · CPC title