CN104571947A - Method for partitioning hard disk domains in storage array, as well as controller and storage array - Google Patents

Abstract

The embodiment of the invention discloses a method for partitioning hard disk domains in a storage array, as well as a controller and the storage array. The method comprises the following steps: firstly, determining a first hard disk domain and a second hard disk domain, wherein the space utilization ratio of the first hard disk domain is greater than that of the second hard disk domain, a difference between the space utilization ratio of the first hard disk domain and that of the second hard disk domain is greater than a preset threshold, and the space utilization ratio is equal to a ratio of the used space capacity of the hard disk domain to the space sum capacity of the hard disk domain; then calculating the number K needed to be reduced in the second hard disk domain and transferring the data stored in K hard disks of the second hard disk domain into other hard disks of the second hard disk domain so as to obtain K idle hard disks, wherein K is an integer of more than or equal to 1; finally, configuring the K idle hard disks into the first hard disk domain. By implementing the method, the space resource utilization rate of the hard disks can be improved under the condition that the unbalanced space utilization rate of the hard disk domain is relieved.

Description

A kind of method and controller, storage array dividing hard disk territory in storage array

Technical field

The present invention relates to computer memory technical field, be specifically related to a kind of in storage array, divide hard disk territory method and controller, storage array.

Background technology

Storage array is made up of a large amount of hard disk, when using storage array storage service data, consider from the angle of business demand and reliability, storage array can be divided into multiple hard disk territory by user, and each hard disk territory comprises tens or up to a hundred pieces of hard disks, user can configure different business according to business demand in different hard disk territories, namely in different hard disk territories, stores different business datums.As time goes on, the quantity of the business datum that user stores changes, and the unbalanced situation of the space availability ratio between hard disk territory is also more and more serious, which results in the problem that hard disk pressure is unbalanced, hard disk life-span reduces and service feature fluctuates.

In order to solve the problem, current exist following scheme: in the hard disk territory that space availability ratio is high, increase new hard disk with the space availability ratio between balanced hard disk territory, but this scheme brings certain cost overhead to user and causes the problem of the hard drive space wasting of resources in the low hard disk territory of space availability ratio.

Summary of the invention

The embodiment of the invention discloses a kind of in storage array, divide hard disk territory method and controller, storage array, between alleviation hard disk territory, hard drive space resource utilization can be improved in the unbalanced situation of space availability ratio.

Embodiment of the present invention first aspect discloses a kind of method dividing hard disk territory in storage array, described storage array at least comprises controller and two hard disk territories, each hard disk territory comprises multiple hard disk, and described method is performed by described controller, and described method comprises:

Determine the first hard disk territory and the second hard disk territory, the space availability ratio in described first hard disk territory is greater than the space availability ratio in described second hard disk territory, and the difference of the space availability ratio in the space availability ratio in described first hard disk territory and described second hard disk territory is greater than predetermined threshold value, described space availability ratio equals the ratio of the space total volume in spatial content that hard disk territory used and this hard disk territory;

Calculate in described second hard disk territory the number K of hard disk needing to reduce, described K be more than or equal to 1 integer;

By the Data Migration that stores in K the hard disk in described second hard disk territory in other hard disk in described second hard disk territory, to obtain K free hard disk;

A described K free hard disk is configured in described first hard disk territory.

In the first possible implementation of embodiment of the present invention first aspect, the space availability ratio that described second hard disk territory is reduced after K hard disk is equal with the space availability ratio that described first hard disk territory increases after K hard disk.

In conjunction with the first possible implementation of embodiment of the present invention first aspect, in the implementation that the second of embodiment of the present invention first aspect is possible, the number K of the hard disk reduced in the described second hard disk territory of described calculating, is needed to comprise:

Calculate in described second hard disk territory the number K of the hard disk needing to reduce according to formula (1), wherein, described formula (1) is:

$\frac{\mathrm{Usedcap}2}{\mathrm{Totalcap}2-K_0\×\mathrm{Unitcap}2}=\frac{\mathrm{Usedcap}1}{\mathrm{Totalcap}1+K_0\×\mathrm{Unitcap}2}$

Wherein, Usedcap2 is the spatial content that described second hard disk territory has used, Totalcap2 is the space total volume in described second hard disk territory, Unitcap2 is the spatial content of each hard disk in described second hard disk territory, Usedcap1 is the spatial content that described first hard disk territory has used, Totalcap1 is the space total volume in described first hard disk territory, K ₀for needing the number of hard disk that reduces in described second hard disk territory and described K ₀for being greater than the positive number of 1, then K is the K calculated according to described formula (1) ₀value round the integer obtained downwards.

In conjunction with the first possible implementation of embodiment of the present invention first aspect, in the third possible implementation of embodiment of the present invention first aspect, before needing the number K of the hard disk reduced in the described second hard disk territory of described calculating, described method also comprises:

Calculate the spatial content that described second hard disk territory needs to reduce;

The number K of the hard disk reduced is needed to comprise in the described second hard disk territory of described calculating:

Need the spatial content reduced to determine K hard disk according to described second hard disk territory, space total volume and the described second hard disk territory of a described K hard disk need the absolute value of the difference of the spatial content reduced to be minimum value.

In conjunction with the third possible implementation of embodiment of the present invention first aspect, in the 4th kind of possible implementation of embodiment of the present invention first aspect, the described second hard disk territory of described calculating needs the spatial content reduced to comprise:

Calculate the spatial content of described second hard disk territory needs minimizing according to formula (2), wherein, described formula (2) is:

$\frac{\mathrm{Usedcap}2}{\mathrm{Totalcap}2-\mathrm{Minuscap}2}=\frac{\mathrm{Usedcap}1}{\mathrm{Totalcap}1+\mathrm{Minuscap}2}$

Wherein, Usedcap2 is the spatial content that described second hard disk territory has used, Totalcap2 is the space total volume in described second hard disk territory, Usedcap1 is the spatial content that described first hard disk territory has used, Totalcap1 is the space total volume in described first hard disk territory, and Minuscap2 is the spatial content that described second hard disk territory needs to reduce.

Embodiment of the present invention second aspect discloses a kind of controller, and described controller comprises communication interface, and described communication interface is used for communicating with at least two hard disk territories, and each hard disk territory comprises multiple hard disk, and described controller is for performing following operation:

Determine the first hard disk territory and the second hard disk territory, the space availability ratio in described first hard disk territory is greater than the space availability ratio in described second hard disk territory, and the difference of the space availability ratio in the space availability ratio in described first hard disk territory and described second hard disk territory is greater than predetermined threshold value, described space availability ratio equals the ratio of the space total volume in spatial content that hard disk territory used and this hard disk territory;

Calculate in described second hard disk territory the number K of hard disk needing to reduce, described K be more than or equal to 1 integer;

By the Data Migration that stores in K the hard disk in described second hard disk territory in other hard disk in described second hard disk territory, to obtain K free hard disk;

A described K free hard disk is configured in described first hard disk territory.

In the first possible implementation of embodiment of the present invention second aspect, the space availability ratio that described second hard disk territory is reduced after K hard disk is equal with the space availability ratio that described first hard disk territory increases after K hard disk.

In conjunction with the first possible implementation of embodiment of the present invention second aspect, in the implementation that the second of embodiment of the present invention second aspect is possible, described controller calculates in described second hard disk territory and needs the concrete mode of the number K of the hard disk reduced to be:

Calculate in described second hard disk territory the number K of the hard disk needing to reduce according to formula (1), wherein, described formula (1) is:

$\frac{\mathrm{Usedcap}2}{\mathrm{Totalcap}2-K_0\×\mathrm{Unitcap}2}=\frac{\mathrm{Usedcap}1}{\mathrm{Totalcap}1+K_0\×\mathrm{Unitcap}2}$

Wherein, Usedcap2 is the spatial content that described second hard disk territory has used, Totalcap2 is the space total volume in described second hard disk territory, Unitcap2 is the spatial content of each hard disk in described second hard disk territory, Usedcap1 is the spatial content that described first hard disk territory has used, Totalcap1 is the space total volume in described first hard disk territory, K ₀for needing the number of hard disk that reduces in described second hard disk territory and described K ₀for being greater than the positive number of 1, then K is the K calculated according to described formula (1) ₀value round the integer obtained downwards.

In conjunction with the first possible implementation of embodiment of the present invention second aspect, in the third possible implementation of embodiment of the present invention second aspect, described controller is also for performing following operation:

Calculate the spatial content that described second hard disk territory needs to reduce;

Described controller calculates in described second hard disk territory and needs the concrete mode of the number K of the hard disk reduced to be:

Need the spatial content reduced to determine K hard disk according to described second hard disk territory, space total volume and the described second hard disk territory of a described K hard disk need the absolute value of the difference of the spatial content reduced to be minimum value.

In conjunction with the third possible implementation of embodiment of the present invention second aspect, in the 4th kind of possible implementation of embodiment of the present invention second aspect, the concrete mode that described controller calculates the spatial content that described second hard disk territory needs reduce is:

Calculate the spatial content of described second hard disk territory needs minimizing according to formula (2), wherein, described formula (2) is:

$\frac{\mathrm{Usedcap}2}{\mathrm{Totalcap}2-\mathrm{Minuscap}2}=\frac{\mathrm{Usedcap}1}{\mathrm{Totalcap}1+\mathrm{Minuscap}2}$

Wherein, Usedcap2 is the spatial content that described second hard disk territory has used, and Totalcap2 is the space total volume in described second hard disk territory, and Usedcap1 is the spatial content that described first hard disk territory has used,

Totalcap1 is the space total volume in described first hard disk territory, and Minuscap2 is the spatial content that described second hard disk territory needs to reduce.

The embodiment of the present invention third aspect discloses a kind of storage array, and described storage array comprises above-mentioned controller and at least two hard disk territories, and each hard disk territory comprises multiple hard disk.

In the embodiment of the present invention, first controller determines the first hard disk territory and the second hard disk territory, wherein, the space availability ratio in the first hard disk territory is greater than the space availability ratio in the second hard disk territory, the difference of the space availability ratio in the first hard disk territory and the space availability ratio in the second hard disk territory is greater than predetermined threshold value, and space availability ratio equals the ratio of the space total volume in spatial content that hard disk territory used and this hard disk territory, then calculating in the second hard disk territory needs the number K of the hard disk reduced and by other hard disk in Data Migration to the second hard disk territory of storing in K the hard disk in the second hard disk territory, to obtain K free hard disk, wherein, K be more than or equal to 1 integer, finally K free hard disk is configured in the first hard disk territory.Implement the embodiment of the present invention and between alleviation hard disk territory, hard drive space resource utilization can be improved in the unbalanced situation of space availability ratio.

Accompanying drawing explanation

In order to be illustrated more clearly in the technical scheme in the embodiment of the present invention, be briefly described to the accompanying drawing used required in embodiment below, apparently, accompanying drawing in the following describes is only some embodiments of the present invention, for those of ordinary skill in the art, under the prerequisite not paying creative work, other accompanying drawing can also be obtained according to these accompanying drawings.

Fig. 1 is the structural representation of a kind of storage array disclosed in the embodiment of the present invention;

Fig. 2 is a kind of schematic flow sheet dividing the method in hard disk territory in storage array disclosed in the embodiment of the present invention.

Embodiment

Below in conjunction with the accompanying drawing in the embodiment of the present invention, be clearly and completely described the technical scheme in the embodiment of the present invention, obviously, described embodiment is only the present invention's part embodiment, instead of whole embodiments.Based on the embodiment in the present invention, those of ordinary skill in the art, not making the every other embodiment obtained under creative work prerequisite, belong to the scope of protection of the invention.

The embodiment of the invention discloses a kind of in storage array, divide hard disk territory method and controller, storage array, between alleviation hard disk territory, hard drive space resource utilization can be improved in the unbalanced situation of space availability ratio.

A kind of method dividing hard disk territory in storage array disclosed in embodiment, the embodiment of the invention discloses a kind of storage array for a better understanding of the present invention, and as shown in Figure 1, Fig. 1 is the structural representation of a kind of storage array disclosed in the embodiment of the present invention.As shown in Figure 1, this storage array 100 at least comprises controller 101 and two hard disk territories (as 1 to hard disk territory, the hard disk territory N in Fig. 1, wherein, N is more than or equal to 2), and each hard disk territory comprises multiple hard disk, controller 101 can comprise communication interface 1011, storer 1012 and processor 1013, controller 101 can be communicated with at least two hard disk territories by communication interface 1011, wherein, batch processing code is stored in storer 1012, controller 101 can call the program code in storer 1012 by processor 1013, for performing following operation:

Determine the first hard disk territory and the second hard disk territory, wherein, the space availability ratio in the first hard disk territory is greater than the space availability ratio in the second hard disk territory, and the difference of the space availability ratio in the first hard disk territory and the space availability ratio in the second hard disk territory is greater than predetermined threshold value and space availability ratio equals the ratio of the space total volume in spatial content that hard disk territory used and this hard disk territory;

Calculate in the second hard disk territory the number K of hard disk needing to reduce, wherein, K be more than or equal to 1 integer;

By in other hard disk in Data Migration to the second hard disk territory of storing in K the hard disk in the second hard disk territory, to obtain K free hard disk;

K free hard disk is configured in the first hard disk territory.

Optionally, the space availability ratio after the second hard disk territory minimizing K hard disk is equal with the space availability ratio that the first hard disk territory increases after K hard disk.

Optionally, controller 101 calculates in the second hard disk territory and needs the concrete mode of number K of the hard disk reduced to be:

Calculate in the second hard disk territory the number K of the hard disk needing to reduce according to formula (1), wherein, formula (1) is:

$\frac{\mathrm{Usedcap}2}{\mathrm{Totalcap}2-K_0\×\mathrm{Unitcap}2}=\frac{\mathrm{Usedcap}1}{\mathrm{Totalcap}1+K_0\×\mathrm{Unitcap}2}$

Wherein, Usedcap2 is the spatial content that the second hard disk territory has used, Totalcap2 is the space total volume in the second hard disk territory, Unitcap2 is the spatial content of each hard disk in the second hard disk territory, Usedcap1 is the spatial content that the first hard disk territory has used, Totalcap1 is the space total volume in the first hard disk territory, K ₀be the number of hard disk and K that need in the second hard disk territory to reduce ₀for being greater than the positive number of 1, then K is the K calculated according to formula (1) ₀value round the integer obtained downwards.

Optionally, controller 101 calls the program code in storer 1012 by processor 1013, also for performing following operation:

Calculate the spatial content that the second hard disk territory needs to reduce.

Controller 101 calculates in the second hard disk territory and needs the concrete mode of number K of the hard disk reduced to be:

Need the spatial content reduced to determine K hard disk according to the second hard disk territory, wherein, the space total volume of K hard disk and the second hard disk territory need the absolute value of the difference of the spatial content reduced to be minimum value.

Optionally, controller 101 calculates the second hard disk territory needs the concrete mode of spatial content reduced to be:

Calculate the spatial content of the second hard disk territory needs minimizing according to formula (2), wherein, formula (2) is:

$\frac{\mathrm{Usedcap}2}{\mathrm{Totalcap}2-\mathrm{Minuscap}2}=\frac{\mathrm{Usedcap}1}{\mathrm{Totalcap}1+\mathrm{Minuscap}2}$

Wherein, Usedcap2 is the spatial content that the second hard disk territory has used, Totalcap2 is the space total volume in the second hard disk territory, Usedcap1 is the spatial content that the first hard disk territory has used, Totalcap1 is the space total volume in the first hard disk territory, and Minuscap2 is the spatial content that the second hard disk territory needs to reduce.

In the embodiment of the present invention, controller 101 can be the server comprising storer, processor and communication interface, and the embodiment of the present invention does not limit.

Refer to Fig. 2, Fig. 2 is a kind of schematic flow sheet dividing the method in hard disk territory in storage array disclosed in the embodiment of the present invention.Wherein, the method shown in Fig. 2 can be applied in the storage array 100 shown in Fig. 1 and the method can be performed by the controller 101 in storage array 100.As shown in Figure 2, the method can comprise the following steps:

S201, determine the first hard disk territory and the second hard disk territory.

In the embodiment of the present invention, the space availability ratio in the first hard disk territory is greater than the space availability ratio in the second hard disk territory and the difference of the space availability ratio in the space availability ratio in the first hard disk territory and the second hard disk territory is greater than predetermined threshold value, wherein, space availability ratio can equal the ratio of the space total volume in spatial content that hard disk territory used and this hard disk territory, also can equal the ratio of the spatial content used of arbitrary hard disk and the space total volume of this arbitrary hard disk in hard disk territory, the embodiment of the present invention does not limit.

In the embodiment of the present invention, when storage array comprises two hard disk territories, the hard disk territory that space availability ratio is large is the first hard disk territory, the hard disk territory that space availability ratio is little is the second hard disk territory, and when the difference of the space availability ratio in the first hard disk territory and the space availability ratio in the second hard disk territory is greater than predetermined threshold value, controller just performs step S202.

In the embodiment of the present invention, when storage array comprises plural hard disk territory, suppose the number in hard disk territory be N (N be greater than 2 integer), N number of space availability ratio in N number of hard disk territory can first sort according to size by controller, then in the N number of space availability ratio after comparative sorting, whether the absolute value of the difference of M space availability ratio and (N-M+1) individual space availability ratio is greater than predetermined threshold value, if, then determine that the hard disk territory that in the hard disk territory that hard disk territory corresponding to M space availability ratio is corresponding with (N-M+1) individual space availability ratio, space availability ratio is larger is the first hard disk territory, the hard disk territory that in the hard disk territory that hard disk territory corresponding to M space availability ratio is corresponding with (N-M+1) individual space availability ratio, space availability ratio is less is the second hard disk territory, afterwards, controller performs step S202, wherein, M is for being more than or equal to 1 and being less than or equal to the integer of (N-M+1).For example, when N equals 50, the 1st space availability ratio in 50 space availability ratio after sequence and the 50th space availability ratio compare by controller, the 2nd space availability ratio and the 49th space availability ratio are compared, by that analogy.

In the embodiment of the present invention, predetermined threshold value can be 15%, 20% or 25% etc., and the embodiment of the present invention does not limit.

S202, calculate in the second hard disk territory the number K of hard disk needing to reduce.

In the embodiment of the present invention, K be more than or equal to 1 integer.

S203, by other hard disk in Data Migration to the second hard disk territory of storing in K the hard disk in the second hard disk territory, to obtain K free hard disk

In the embodiment of the present invention, the data stored in K hard disk can migrate in other hard disk in the second hard disk territory by controller uniformly, and the embodiment of the present invention does not limit.

S204, K free hard disk to be configured in the first hard disk territory.

In the embodiment of the present invention, K free hard disk is configured to after in the first hard disk territory by controller, can also the business datum stored in the first hard disk territory be evenly stored in all hard disks in the first hard disk territory, the pressure of other hard disk in the first hard disk territory can be alleviated like this.

In the embodiment of the present invention, the space availability ratio that the second hard disk territory is reduced after K hard disk is equal with the space availability ratio that the first hard disk territory increases after K hard disk.

As the optional embodiment of one, when in the second hard disk territory, the spatial content of each hard disk is equal, controller calculates in the second hard disk territory needs the number K of the hard disk reduced to comprise:

Calculate in the second hard disk territory the number K of the hard disk needing to reduce according to formula (1), wherein, formula (1) is:

$\frac{\mathrm{Usedcap}2}{\mathrm{Totalcap}2-K_0\×\mathrm{Unitcap}2}=\frac{\mathrm{Usedcap}1}{\mathrm{Totalcap}1+K_0\×\mathrm{Unitcap}2}$

Wherein, Usedcap2 is the spatial content that the second hard disk territory has used, Totalcap2 is the space total volume in the second hard disk territory, Unitcap2 is the spatial content of each hard disk in the second hard disk territory, Usedcap1 is the spatial content that the first hard disk territory has used, Totalcap1 is the space total volume in the first hard disk territory, K ₀be the number of hard disk and K that need in the second hard disk territory to reduce ₀for being greater than the positive number of 1, then K is the K calculated according to formula (1) ₀value round the integer obtained downwards.

In the embodiment of the present invention, after the number K determining in the second hard disk territory the hard disk needing to reduce according to formula (1), controller can choose K hard disk at random from all hard disks in the second hard disk territory, also can choose K lower hard disk of the severity level of the business datum of storage according to the severity level of the business datum of each hard-disc storage in the second hard disk territory from the second hard disk territory, the embodiment of the present invention does not limit.

As the optional embodiment of one, before step S202, the method can also comprise:

Calculate the spatial content that the second hard disk territory needs to reduce.

Controller calculates in the second hard disk territory needs the number K of the hard disk reduced to comprise:

Need the spatial content reduced to determine K hard disk according to the second hard disk territory, wherein, the space total volume of K hard disk and the second hard disk territory need the absolute value of the difference of the spatial content reduced to be minimum value.

As the optional embodiment of one, controller calculates the second hard disk territory needs the spatial content reduced to comprise:

Calculate the spatial content of the second hard disk territory needs minimizing according to formula (2), wherein, formula (2) is:

$\frac{\mathrm{Usedcap}2}{\mathrm{Totalcap}2-\mathrm{Minuscap}2}=\frac{\mathrm{Usedcap}1}{\mathrm{Totalcap}1+\mathrm{Minuscap}2}$

Wherein, Usedcap2 is the spatial content that the second hard disk territory has used, Totalcap2 is the space total volume in the second hard disk territory, Usedcap1 is the spatial content that the first hard disk territory has used, Totalcap1 is the space total volume in the first hard disk territory, and Minuscap2 is the spatial content that the second hard disk territory needs to reduce.

In the embodiment of the present invention, first controller determines the first hard disk territory and the second hard disk territory, wherein, the space availability ratio in the first hard disk territory is greater than the space availability ratio in the second hard disk territory, the difference of the space availability ratio in the first hard disk territory and the space availability ratio in the second hard disk territory is greater than predetermined threshold value, and space availability ratio equals the ratio of the space total volume in spatial content that hard disk territory used and this hard disk territory, then calculating in the second hard disk territory needs the number K of the hard disk reduced and by other hard disk in Data Migration to the second hard disk territory of storing in K the hard disk in the second hard disk territory, to obtain K free hard disk, wherein, K be more than or equal to 1 integer, finally K free hard disk is configured in the first hard disk territory.Implement the embodiment of the present invention and between alleviation hard disk territory, hard drive space resource utilization can be improved in the unbalanced situation of space availability ratio.

One of ordinary skill in the art will appreciate that all or part of step in the various methods of above-described embodiment is that the hardware that can carry out instruction relevant by program has come, this program can be stored in a computer-readable recording medium, storage medium can comprise: flash disk, ROM (read-only memory) (Read-Only Memory, ROM), random access device (Random Access Memory, RAM), disk or CD etc.

Above to the embodiment of the present invention provide a kind of in storage array, divide hard disk territory method and controller, storage array be described in detail, apply specific case herein to set forth principle of the present invention and embodiment, the explanation of above embodiment just understands method of the present invention and core concept thereof for helping; Meanwhile, for one of ordinary skill in the art, according to thought of the present invention, all will change in specific embodiments and applications, in sum, this description should not be construed as limitation of the present invention.

Claims (11)

1. in storage array, divide the method in hard disk territory, it is characterized in that, described storage array at least comprises controller and two hard disk territories, and each hard disk territory comprises multiple hard disk, and described method is performed by described controller, and described method comprises:

Determine the first hard disk territory and the second hard disk territory, the space availability ratio in described first hard disk territory is greater than the space availability ratio in described second hard disk territory, and the difference of the space availability ratio in the space availability ratio in described first hard disk territory and described second hard disk territory is greater than predetermined threshold value, described space availability ratio equals the ratio of the space total volume in spatial content that hard disk territory used and this hard disk territory;

Calculate in described second hard disk territory the number K of hard disk needing to reduce, described K be more than or equal to 1 integer;

By the Data Migration that stores in K the hard disk in described second hard disk territory in other hard disk in described second hard disk territory, to obtain K free hard disk;

A described K free hard disk is configured in described first hard disk territory.

2. method according to claim 1, is characterized in that, the space availability ratio that described second hard disk territory is reduced after K hard disk is equal with the space availability ratio that described first hard disk territory increases after K hard disk.

3. method according to claim 2, is characterized in that, needs the number K of the hard disk reduced to comprise in the described second hard disk territory of described calculating:

Calculate in described second hard disk territory the number K of the hard disk needing to reduce according to formula (1), wherein, described formula (1) is:

$\frac{\mathrm{Usedcap}2}{\mathrm{Totalcap}2-K_0\×\mathrm{Unitcap}2}=\frac{\mathrm{Usedcap}1}{\mathrm{Totalcap}1+K_0\×\mathrm{Unitcap}2}$

Wherein, Usedcap2 is the spatial content that described second hard disk territory has used, Totalcap2 is the space total volume in described second hard disk territory, Unitcap2 is the spatial content of each hard disk in described second hard disk territory, Usedcap1 is the spatial content that described first hard disk territory has used, Totalcap1 is the space total volume in described first hard disk territory, K ₀for needing the number of hard disk that reduces in described second hard disk territory and described K ₀for being greater than the positive number of 1, then K is the K calculated according to described formula (1) ₀value round the integer obtained downwards.

4. method according to claim 2, is characterized in that, before needing the number K of the hard disk reduced in the described second hard disk territory of described calculating, described method also comprises:

Calculate the spatial content that described second hard disk territory needs to reduce;

The number K of the hard disk reduced is needed to comprise in the described second hard disk territory of described calculating:

Need the spatial content reduced to determine K hard disk according to described second hard disk territory, space total volume and the described second hard disk territory of a described K hard disk need the absolute value of the difference of the spatial content reduced to be minimum value.

5. method according to claim 4, is characterized in that, the described second hard disk territory of described calculating needs the spatial content reduced to comprise:

Calculate the spatial content of described second hard disk territory needs minimizing according to formula (2), wherein, described formula (2) is:

$\frac{\mathrm{Usedcap}2}{\mathrm{Totalcap}2-\mathrm{Minuscap}2}=\frac{\mathrm{Usedcap}1}{\mathrm{Totalcap}1+\mathrm{Minuscap}2}$

Wherein, Usedcap2 is the spatial content that described second hard disk territory has used, Totalcap2 is the space total volume in described second hard disk territory, Usedcap1 is the spatial content that described first hard disk territory has used, Totalcap1 is the space total volume in described first hard disk territory, and Minuscap2 is the spatial content that described second hard disk territory needs to reduce.

6. a controller, is characterized in that, described controller comprises communication interface, and described communication interface is used for communicating with at least two hard disk territories, and each hard disk territory comprises multiple hard disk, and described controller is for performing following operation:

Determine the first hard disk territory and the second hard disk territory, the space availability ratio in described first hard disk territory is greater than the space availability ratio in described second hard disk territory, and the difference of the space availability ratio in the space availability ratio in described first hard disk territory and described second hard disk territory is greater than predetermined threshold value, described space availability ratio equals the ratio of the space total volume in spatial content that hard disk territory used and this hard disk territory;

Calculate in described second hard disk territory the number K of hard disk needing to reduce, described K be more than or equal to 1 integer;

By the Data Migration that stores in K the hard disk in described second hard disk territory in other hard disk in described second hard disk territory, to obtain K free hard disk;

A described K free hard disk is configured in described first hard disk territory.

7. controller according to claim 6, is characterized in that, the space availability ratio that described second hard disk territory is reduced after K hard disk is equal with the space availability ratio that described first hard disk territory increases after K hard disk.

8. controller according to claim 7, is characterized in that, described controller calculates in described second hard disk territory and needs the concrete mode of the number K of the hard disk reduced to be:

Calculate in described second hard disk territory the number K of the hard disk needing to reduce according to formula (1), wherein, described formula (1) is:

$\frac{\mathrm{Usedcap}2}{\mathrm{Totalcap}2-K_0\×\mathrm{Unitcap}2}=\frac{\mathrm{Usedcap}1}{\mathrm{Totalcap}1+K_0\×\mathrm{Unitcap}2}$

Wherein, Usedcap2 is the spatial content that described second hard disk territory has used, Totalcap2 is the space total volume in described second hard disk territory, Unitcap2 is the spatial content of each hard disk in described second hard disk territory, Usedcap1 is the spatial content that described first hard disk territory has used, Totalcap1 is the space total volume in described first hard disk territory, K ₀for needing the number of hard disk that reduces in described second hard disk territory and described K ₀for being greater than the positive number of 1, then K is the K calculated according to described formula (1) ₀value round the integer obtained downwards.

9. controller according to claim 7, is characterized in that, described controller is also for performing following operation:

Calculate the spatial content that described second hard disk territory needs to reduce;

Described controller calculates in described second hard disk territory and needs the concrete mode of the number K of the hard disk reduced to be:

Need the spatial content reduced to determine K hard disk according to described second hard disk territory, space total volume and the described second hard disk territory of a described K hard disk need the absolute value of the difference of the spatial content reduced to be minimum value.

10. controller according to claim 9, is characterized in that, the concrete mode that described controller calculates the spatial content that described second hard disk territory needs reduce is:

Calculate the spatial content of described second hard disk territory needs minimizing according to formula (2), wherein, described formula (2) is:

$\frac{\mathrm{Usedcap}2}{\mathrm{Totalcap}2-\mathrm{Minuscap}2}=\frac{\mathrm{Usedcap}1}{\mathrm{Totalcap}1+\mathrm{Minuscap}2}$

Wherein, Usedcap2 is the spatial content that described second hard disk territory has used, Totalcap2 is the space total volume in described second hard disk territory, Usedcap1 is the spatial content that described first hard disk territory has used, Totalcap1 is the space total volume in described first hard disk territory, and Minuscap2 is the spatial content that described second hard disk territory needs to reduce.

11. 1 kinds of storage arrays, is characterized in that, described storage array comprises controller as described in any one of claim 6 ~ 10 and at least two hard disk territories, and each hard disk territory comprises multiple hard disk.