CN106371950A - Method and device for achieving RAID level conversion - Google Patents

Abstract

The invention discloses a method and device for realizing RAID level conversion, comprising: when receiving an independent redundant disk array (RAID) level conversion command, judging according to the pre-recorded occupation information of the current RAID level disk and the remaining available space information of the system Whether the remaining available space of the system meets the requirements of RAID level conversion; when the requirements of RAID level conversion are met, a new RAID level disk is established in the remaining available space of the system, and the mapping relationship between the occupied address of the current RAID level disk and the address of the new RAID level disk is established to complete the RAID level conversion. The method of the invention can realize RAID level conversion without data transfer, avoiding the problem of service interruption caused by data transfer; establishing a new RAID level disk is fast and reduces the time consumption of level conversion.

Description

A method and device for realizing RAID level conversion

technical field

The invention relates to disk array technology, in particular to a method and device for realizing independent redundant disk array (RAID) level conversion.

Background technique

Redundant Array of Independent Disks (RAID, Redundant Array of Independent Disk) is a combination of multiple independent hard disks (physical hard disks) in different ways to form a hard disk group (logical hard disk), to provide higher storage than a single hard disk. Performance, technology that provides data backup capabilities. Different ways to form a disk array form a corresponding RAID level. Different RAID levels have corresponding performance in terms of data reliability and read/write performance.

Currently, RAID is generally divided into RAID0, RAID1, RAID3, RAID5, RAID6, RAID10 and other levels. In order to meet the availability, and/or performance, and/or capacity requirements of the storage system, the conversion of each level of RAID is selected. For example, to save space, convert a RAID level of RAID1 to a RAID level of RAID5. To improve reliability, convert the RAID level of RAID5 to the RAID level of RAID6. The patent with the application number CN200910174224.3 discloses "a method and device for RAID level conversion", which specifically discloses: when performing the level change operation, the data is moved in advance, and the data in the RAID format before the level change is converted into The data in the RAID format is recalculated, and the RAID level change operation is completed only after the entire data migration is completed, that is, the RAID level conversion is completed; in this method, the user can perform new business operations only after the level change is completed. During the upgrading process, new business operations cannot be performed, which may cause business interruption and affect the overall business performance. The patent No. US2004133743 discloses "Raid apparatus and logical device expansion methodthereof", which specifically discloses the use of strips to handle RAID level changes, and the use of strips to handle level changes. It takes a lot of time, and the user needs to wait for the upgrade to complete before proceeding with business, which may cause business interruption.

Contents of the invention

In order to solve the above technical problems, the present invention provides a method and device for implementing RAID level conversion, which can quickly implement level conversion without interrupting services.

In order to achieve the purpose of the present invention, the present invention provides a kind of method that realizes RAID level conversion, when receiving redundant array of independent disks RAID level conversion instruction, comprising:

Judging whether the remaining available space of the system meets the requirements of RAID level conversion according to the pre-recorded occupation information of the current RAID level disk and the information of the remaining available space of the system;

When the requirements for RAID level conversion are met, a new RAID level disk is created in the remaining available space of the system, and the mapping relationship between the occupied address of the current RAID level disk and the address of the new RAID level disk is established to complete the RAID level conversion.

Further, when the remaining available space of the system does not meet the requirements for RAID level conversion, the method further includes: determining that the level conversion fails and feeding back information about the level conversion failure to the user.

Further, the method also includes: when the system is idle,

Convert the data on the current RAID level disk according to the data format of the new RAID level;

According to the mapping association, the data on the current RAID level disk that has completed the data format conversion is transferred to the disk space corresponding to the address of the new RAID level disk.

Further, the method also includes:

The address information occupied by the disks of the new RAID level and the address information of the occupied space of each disk in the system are recorded.

Further, when the transfer of the data on the current RAID level disk is not completed, the method also includes:

When reading business data, query whether the current RAID level disk contains the business data, if it contains the business data, then read the business data; if it does not contain the business data, then according to the mapping relationship, Read the business data from the new RAID level disk;

When writing business data, according to the start address and length of the written business data, it is judged whether the new RAID level disk contains enough space for writing business data, and when there is enough space for writing business data, write Business data, and update the address information occupied by the new RAID level disk and the address mapping relationship; when there is not enough space for writing business data, feedback business data writing failure.

Further, the mapping association specifically includes:

The association relationship between the current RAID level and the starting address of the space of the new RAID level in each disk in the system.

On the other hand, the present application also provides a device for implementing RAID level conversion, including: a judging unit and a level conversion unit; wherein,

The judging unit is configured to judge whether the remaining available space of the system meets the requirements of the RAID level conversion according to the pre-recorded occupancy information of the current RAID level disk and the information of the remaining available space of the system when receiving the RAID level conversion instruction;

The level conversion unit is used to judge that when the judging unit meets the requirements of the RAID level conversion, a new RAID level disk is established in the remaining available space of the system, and the mapping relationship between the occupied address of the current RAID level disk and the address of the new RAID level disk is established, Complete RAID level conversion.

Further, the device further includes a feedback unit, used for determining that the level conversion fails and feeding back information about the level conversion failure to the user when the judging unit determines that the remaining available space of the system does not meet the requirements for RAID level conversion.

Further, the device also includes a data conversion and transfer unit, which is used to, when the system is idle,

Convert the data on the current RAID level disk according to the data format of the new RAID level;

According to the mapping association, the data on the current RAID level disk that has completed the data format conversion is transferred to the disk space corresponding to the address of the new RAID level disk.

Further, the device further includes a recording unit, configured to record occupation information of disks of the current RAID level, information of remaining available space in the system, address information occupied by disks of the new RAID level, and address information of occupied spaces of disks in the system.

Further, the device also includes a read and write unit, configured to, when the transfer of data on the current RAID level disk is not completed,

When reading business data, query whether the current RAID level disk contains the business data, if the business data is included, the business data is read; if the business data is not included, then according to the level conversion unit established The above-mentioned mapping association relationship is read from the new RAID level disk to read the business data;

When writing business data, according to the start address and length of the written business data, it is judged whether the new RAID level disk contains enough space for writing business data, and when there is enough space for writing business data, write Business data, and update the address information occupied by the new RAID level disk of the recording unit and the address mapping relationship established by the level conversion unit; when there is not enough space for business data writing, the feedback business data write failure.

Further, the mapping association specifically includes:

The association relationship between the current RAID level and the starting address of the space of the new RAID level in each disk in the system.

Compared with the prior art, the technical solution of the present application includes: when receiving a Redundant Array of Independent Disks (RAID) level conversion command, judging the remaining available space of the system according to the pre-recorded occupancy information of the current RAID level disk and the information of the remaining available space of the system Whether it meets the requirements of RAID level conversion; when the requirements of RAID level conversion are met, a new RAID level disk is created in the remaining available space of the system, and the mapping relationship between the occupied address of the current RAID level disk and the address of the new RAID level disk is established to complete the RAID level convert. The method of the invention can realize RAID level conversion without data transfer, avoiding the problem of service interruption caused by data transfer; establishing a new RAID level disk is fast and reduces the time consumption of level conversion.

Description of drawings

The accompanying drawings described here are used to provide a further understanding of the present invention and constitute a part of the application. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations to the present invention. In the attached picture:

Fig. 1 is the flow chart of the method that the present invention realizes RAID level conversion;

Fig. 2 is the structural diagram of the device that realizes RAID level conversion of the present invention;

Fig. 3 is the flowchart of the method of the first embodiment of the present invention;

Fig. 4 is the flowchart of the method of the second embodiment of the present invention;

Fig. 5 is the flowchart of the method of the third embodiment of the present invention;

6 is a schematic diagram of the composition of the current RAID level disk in the fourth embodiment of the present invention;

7 is a schematic diagram of the composition of a new RAID level disk in the fourth embodiment of the present invention;

FIG. 8 is a flowchart of a method according to a fourth embodiment of the present invention.

detailed description

In order to make the purpose, technical solution and advantages of the present invention more clear, the embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings. It should be noted that, in the case of no conflict, the embodiments in the present application and the features in the embodiments can be combined arbitrarily with each other.

Fig. 1 is the flow chart of the method that the present invention realizes RAID level conversion, as shown in Figure 1, when receiving redundant array of independent disks RAID level conversion instruction, comprises:

Step 100, judging whether the remaining available space of the system meets the requirements of RAID level conversion according to the pre-recorded occupation information of the current RAID level disk and the information of the remaining available space of the system;

It should be noted that it is common knowledge of those skilled in the art to judge whether the remaining available space of the system satisfies the requirements for RAID level conversion; generally, when the remaining available space of the system is greater than or equal to the size occupied by the current RAID level disk, it meets the requirements of RAID level conversion. requirements and will not be repeated here.

Step 101, when meeting the requirements of RAID level conversion, create a new RAID level disk in the remaining available space of the system, and establish a mapping relationship between the occupied address of the current RAID level disk and the address of the new RAID level disk, and complete the RAID level conversion.

When the remaining available space of the system does not meet the requirements of the RAID level conversion, the method of the present invention further includes: determining that the level conversion fails and feeding back information about the level conversion failure to the user.

The method of the present invention also includes: when the system is idle,

Convert the data on the disk of the current RAID level according to the data format of the new RAID level;

According to the mapping relationship, the data on the current RAID level disk that has completed the data format conversion is transferred to the disk space corresponding to the address of the new RAID level disk.

The inventive method also includes:

Record the address information occupied by the new RAID level disk and the address information of the occupied space of each disk in the system.

When the transfer of data on the current RAID level disk is not completed, the method of the present invention also includes:

When reading business data, query whether the current RAID level disk contains business data, if it contains business data, read the business data; if it does not contain business data, read the business data from the new RAID level disk according to the mapping relationship;

When writing business data, judge whether the new RAID level disk contains enough space for writing business data according to the start address and length of the written business data. When there is enough space for writing business data, write business data , and update the address information and address mapping relationship occupied by the new RAID level disk; if there is not enough space for writing business data, it will report that the writing of business data failed.

It should be noted that whether the new RAID level disk contains enough space for writing business data is a common technical means for those skilled in the art; generally, for example, use 4 disks with a capacity of 1T to create a RAID5 with a capacity of 600G (Among them, 1 check disk, and the other 3 are used as data disks), then the capacity of RAID5 is 600G, the used space on each disk is 200G, and the remaining space on each disk is 800G. If you want to change the level to RAID6 (including 2 check disks and the others are data disks), each disk needs to occupy 300G, while the original remaining space is 800G, so the operation of RAID level conversion can be performed.

The mapping relationship specifically includes:

The relationship between the current RAID level and the starting address of the space of the new RAID level in each disk in the system.

The method of the invention can realize RAID level conversion without data transfer, avoiding the problem of service interruption caused by data transfer; establishing a new RAID level disk is fast and reduces the time consumption of level conversion.

Fig. 2 is the structural flow chart of the device that realizes RAID level conversion of the present invention, as shown in Fig. 2, comprises: judging unit, level conversion unit; Wherein,

The judging unit is configured to judge whether the remaining available space of the system meets the requirements of the RAID level conversion according to the pre-recorded occupancy information of the current RAID level disk and the information of the remaining available space of the system when receiving the RAID level conversion instruction;

The level conversion unit is used to judge that when the judging unit meets the requirements of the RAID level conversion, a new RAID level disk is established in the remaining available space of the system, and the mapping relationship between the occupied address of the current RAID level disk and the address of the new RAID level disk is established, Complete RAID level conversion.

The mapping relationship specifically includes:

The relationship between the current RAID level and the starting address of the space of the new RAID level in each disk in the system.

The device of the present invention further includes a feedback unit, which is used for determining that the level conversion fails and feeding back information about the level conversion failure to the user when the judging unit judges that the remaining available space of the system does not meet the requirements for RAID level conversion.

The device of the present invention also includes a data conversion and transfer unit for when the system is idle,

Convert the data on the disk of the current RAID level according to the data format of the new RAID level;

According to the mapping relationship, the data on the current RAID level disk that has completed the data format conversion is transferred to the disk space corresponding to the address of the new RAID level disk.

The device of the present invention also includes a recording unit for recording the occupation information of the current RAID level disk, the remaining available space information of the system, the address information occupied by the new RAID level disk, and the address information of the occupied space of each disk in the system.

The device of the present invention also includes a read and write unit, which is used for when the transfer of data on the current RAID level disk is not completed,

When reading business data, query whether the current RAID level disk contains business data. If it contains business data, read the business data; read business data;

When writing business data, judge whether the new RAID level disk contains enough space for writing business data according to the start address and length of the written business data. When there is enough space for writing business data, write business data , and update the address information occupied by the new RAID level disk of the recording unit and the address mapping relationship established by the level conversion unit; when there is not enough space for writing business data, feedback business data writing failure.

The method of the present invention will be clearly and detailedly described through specific examples below, and the examples are only used to illustrate the present invention, and are not intended to limit the protection scope of the present invention.

Example 1

Fig. 3 is a flow chart of the method of the first embodiment of the present invention, as shown in Fig. 3, comprising:

Step 300, when receiving a redundant array of independent disks RAID level conversion command, read the pre-recorded information about the remaining available space of the system.

Step 301, judging whether the remaining available space of the system meets the requirements of RAID level conversion according to the occupancy information of the current RAID level disk and the information of the remaining available space of the system;

Here, the occupancy information of the current RAID level disk and the remaining free space information of the system can be recorded through the corresponding list. Taking the maximum number of data disks that a RAID can support is 16, and the maximum number of verification disks is 2 as an example, through the following fields

The field "used space" indicates the space occupied by the disk at the current RAID level;

The field "available space" indicates the remaining available space in the current system, that is, the remaining disk space in the system that can be used to create a new RAID level;

The field "current RAID start" indicates the start address of the disk space on the old RAID level;

The field "current RAID end" indicates the end address of the disk space on the old RAID level;

The field "new RAID start" indicates the start address of the disk space on the new RAID level;

The field "new RAID end" indicates the end address of the disk space on the new RAID level;

The field "D0 start" indicates the starting address of the used disk space on disk D0;

The field "D0 end" indicates the end address of the used disk space on disk D0;

The field "D1 Start" indicates the starting address of the used disk space on disk D1;

The field "D1 end" indicates the end address of the used disk space on disk D1;

The field "D2 Start" indicates the starting address of the used disk space on disk D2;

The field "D2 end" indicates the end address of the used disk space on disk D2;

The field "D3 start" indicates the starting address of the used disk space on disk D3;

The field "D3 end" indicates the end address of the used disk space on disk D3;

The field "D4 start" indicates the starting address of the used disk space on disk D4;

The field "D4 end" indicates the end address of the used disk space on disk D4;

The field "D5 start" indicates the starting address of the used disk space on disk D5;

The field "D5 end" indicates the end address of the used disk space on disk D5;

The field "D6 start" indicates the starting address of the used disk space on disk D6;

The field "D6 end" indicates the end address of the used disk space on disk D6;

The field "D7 start" indicates the starting address of the used disk space on disk D7;

The field "D7 end" indicates the end address of the used disk space on disk D7;

The field "D8 start" indicates the starting address of the used disk space on disk D8;

The field "D8 end" indicates the end address of the used disk space on disk D8;

The field "D9 start" indicates the starting address of the used disk space on disk D9;

The field "D9 end" indicates the end address of the used disk space on disk D9;

The field "D10 start" indicates the starting address of the used disk space on the disk D10;

The field "D10 end" indicates the end address of the used disk space on disk D10;

The field "D11 start" indicates the starting address of the used disk space on the disk D11;

The field "D11 end" indicates the end address of the used disk space on disk D11;

The field "D12 Start" indicates the starting address of the used disk space on the disk D12;

The field "D12 end" indicates the end address of the used disk space on the disk D12;

The field "D13 start" indicates the starting address of the used disk space on the disk D13;

The field "D13 end" indicates the end address of the used disk space on disk D13;

The field "D14 start" indicates the starting address of the used disk space on the disk D14;

The field "D14 end" indicates the end address of the used disk space on disk D14;

The field "D15 start" indicates the starting address of the used disk space on the disk D15;

The field "D15 end" indicates the end address of the used disk space on disk D15;

The field "P start" indicates the starting address of the used disk space on disk P;

The field "P end" indicates the end address of the used disk space on disk P;

The field "Q starts" indicates the starting address of the used disk space on disk Q;

The field "Q end" indicates the end address of the used disk space on disk Q.

Step 302: When the requirements for RAID level conversion are met, create a new RAID level disk in the remaining available space of the system, and establish a mapping relationship between the occupied address of the current RAID level disk and the address of the new RAID level disk, and complete the RAID level conversion. If the requirements for RAID level conversion are not met, feedback level conversion fails.

The mapping relationship specifically includes:

The mapping relationship between the current RAID level and the starting address of the space of the new RAID level in each disk in the system. Taking the new RAID level with 15 data disks and two verification disks P and Q as an example, the mapping relationship includes the following information:

The field "D0" indicates the starting address of the storage data corresponding to the current RAID level and the new RAID level on the disk D0;

The field "D1" indicates the starting address of the storage data corresponding to the current RAID level and the new RAID level on the disk D1;

The field "D2" indicates the starting address of the storage data corresponding to the current RAID level and the new RAID level on the disk D2;

The field "D3" indicates the starting address of the storage data corresponding to the current RAID level and the new RAID level on the disk D3;

The field "D4" indicates the starting address of the storage data corresponding to the current RAID level and the new RAID level on the disk D4;

The field "D5" indicates the starting address of the storage data corresponding to the current RAID level and the new RAID level on the disk D5;

The field "D6" indicates the starting address of the storage data corresponding to the current RAID level and the new RAID level on the disk D6;

The field "D7" represents the starting address of the storage data corresponding to the current RAID level and the new RAID level on the disk D7;

The field "D8" indicates the starting address of the storage data corresponding to the current RAID level and the new RAID level on the disk D8;

The field "D9" represents the starting address of the storage data corresponding to the current RAID level and the new RAID level on the disk D9;

The field "D10" indicates the starting address of the storage data corresponding to the current RAID level and the new RAID level on the disk D10;

The field "D11" indicates the starting address of the storage data corresponding to the current RAID level and the new RAID level on the disk D11;

The field "D12" indicates the starting address of the storage data corresponding to the current RAID level and the new RAID level on the disk D12;

The field "D13" indicates the starting address of the storage data corresponding to the current RAID level and the new RAID level on the disk D13;

The field "D14" indicates the starting address of the storage data corresponding to the current RAID level and the new RAID level on the disk D14;

The field "D15" indicates the starting address of the storage data corresponding to the current RAID level and the new RAID level on the disk D15;

The field "P" indicates the starting address of the storage data corresponding to the current RAID level and the new RAID level on the disk P;

The field "Q" indicates the starting address of data stored on the disk Q corresponding to the current RAID level and the new RAID level.

Step 303: Feedback to the user that the level conversion is successful.

Example 2

After this embodiment establishes the new RAID level disk and the mapping association, complete the RAID level conversion without affecting the business of the system; Fig. 4 is a flow chart of the method of the second embodiment of the present invention, as shown in Fig. 4 , including:

Step 400, according to the instruction of reading business data, query whether the current RAID level disk contains business data; if the current RAID level disk contains business data, execute step 401, read the business data; otherwise, execute step 402.

Step 401, read business data.

Step 402, read service data from the new RAID level disk according to the mapping relationship.

After step 401 or 402 is executed and the service data is read, step 403 is executed.

Step 403, feedback the result of reading business data to the user.

Example 3

After this embodiment establishes the new RAID level disk and the mapping association, complete the RAID level conversion without affecting the business of the system; Fig. 5 is a flow chart of the method of the third embodiment of the present invention, as shown in Fig. 5 , including:

Step 500: Acquire the start address and length of the written service data according to the user's write operation instruction.

Step 501, read the address information occupied by the new RAID level disk, obtain the space available for writing business data, and when judging whether there is enough space for writing business data, execute step 5020; otherwise, execute step 5030;

Step 5020, write business data. This step specifically includes:

According to the obtained start address of the written business data and the information of the mapping association relationship, it is judged whether the written business data is on the disk of the new RAID level or on the disk of the current RAID level.

If the business data to be written is on the disk of the current RAID level, the write address needs to be obtained from the disk of the new RAID level; if the data to be written is on the disk of the new RAID level, write directly to the disk of the new RAID level Enter business data.

Step 5030, feedback the failure of writing business data to the user.

Step 5021 , updating the address information occupied by disks of the new RAID level and the address mapping association.

Step 5022, feedback the operation result of writing business data to the user.

Example 4

6 is a schematic diagram of the composition of the current RAID level disk in the fourth embodiment of the present invention. As shown in FIG.

Fig. 7 is a schematic diagram of the composition of the new RAID level disk in the fourth embodiment of the present invention. As shown in Fig. 7, the new RAID level disk consists of at least two data disks D0 and D1, a parity disk P, and a parity disk Q. .

This embodiment mainly describes the process of transferring data on a disk of a current RAID level to a disk of a new RAID level. Fig. 8 is a flow chart of the method of the fourth embodiment of the present invention, as shown in Fig. 8, including:

Step 800, judging whether the system is idle; specifically,

If the current system has no external or internal read and write operations, it is judged that the system is idle, and when the system is idle, perform step 801; otherwise, perform a read or write operation.

Step 801, look up the mapping relationship, and obtain the addresses of D0, D1 and D2 transferred after the data of D0, D1 and D2 on the RAID5 level disk is converted to the RAID6 level disk;

Step 802, convert the data on the RAID5 level disk according to the data format of the RAID6 level, transfer the data on the RAID5 level disk that completes the data format conversion to the disk space corresponding to the address of the RAID6 level disk, and generate the P and Q disks on the RAID6 disk. test information.

Step 803, updating the address information occupied by the RAID6 level disk and the address mapping association.

Although the embodiments disclosed in the present invention are as above, the described content is only an embodiment adopted for understanding the present invention, and is not intended to limit the present invention. Anyone skilled in the field of the present invention can make any modifications and changes in the form and details of the implementation without departing from the spirit and scope disclosed by the present invention, but the patent protection scope of the present invention must still be The scope defined by the appended claims shall prevail.

Claims (12)

1. A method for realizing RAID level conversion is characterized in that when receiving a RAID level conversion instruction, the method comprises the following steps:

judging whether the remaining available space of the system meets the requirement of RAID level conversion or not according to pre-recorded occupation information of the current RAID level disk and the remaining available space information of the system;

and when the requirement of RAID level conversion is met, establishing a new RAID level disk in the residual available space of the system, and establishing a mapping incidence relation between the occupied address of the current RAID level disk and the address of the new RAID level disk to complete RAID level conversion.

2. The method of claim 1, wherein when the system remaining available space does not meet the requirements for RAID level translation, the method further comprises: determining that the level conversion fails and feeding back information of the level conversion failure to the user.

3. The method of claim 1, further comprising: when the system is in an idle state, the system is in a standby state,

converting the data on the current RAID level disk according to the data format of the new RAID level;

and transferring the data on the current RAID level disk after completing the data format conversion to a disk space corresponding to the address of the new RAID level disk according to the mapping incidence relation.

4. A method according to any one of claims 1 to 3, further comprising:

and recording the address information occupied by the new RAID level disk and the address information of the occupied space of each disk in the system.

5. The method of claim 4, wherein the method further comprises, while the transfer of data to the current RAID level disk is not complete:

when reading the service data, inquiring whether the current RAID level disk contains the service data, and if so, reading the service data; if the service data is not contained, reading the service data from the new RAID level disk according to the mapping association relation;

when writing in the service data, judging whether the new RAID level disk contains enough space for writing in the service data according to the initial address and the length of the written service data, and when the space for writing in the service data is enough, writing in the service data and updating the address information occupied by the new RAID level disk and the address mapping association relation; and when the space for writing the service data is not contained enough, the service data writing failure is fed back.

6. The method according to any one of claims 1 to 3, wherein the mapping association specifically comprises:

and the incidence relation of the initial addresses of the spaces of the current RAID level and the new RAID level in each disk in the system.

7. An apparatus for implementing RAID level translation, comprising: a judging unit, a level converting unit; wherein,

the judging unit is used for judging whether the remaining available space of the system meets the requirement of RAID level conversion or not according to the pre-recorded occupation information of the current RAID level disk and the remaining available space information of the system when receiving the RAID level conversion instruction;

and the level conversion unit is used for establishing a new RAID level disk in the residual available space of the system and establishing a mapping association relation between the occupied address of the current RAID level disk and the address of the new RAID level disk to complete RAID level conversion when the judgment unit judges that the requirement of RAID level conversion is met.

8. The apparatus according to claim 7, further comprising a feedback unit, configured to determine that the level shift fails and feed back information of the level shift failure to a user when the determining unit determines that the remaining available space of the system does not satisfy the requirement of RAID level shift.

9. The apparatus of claim 7, further comprising a data transition transfer unit for transferring data between the first and second processors when the system is idle,

converting the data on the current RAID level disk according to the data format of the new RAID level;

and transferring the data on the current RAID level disk after completing the data format conversion to a disk space corresponding to the address of the new RAID level disk according to the mapping incidence relation.

10. The apparatus according to any one of claims 7 to 9, further comprising a recording unit configured to record occupation information of a current RAID level disk, information of remaining available space of the system, address information occupied by the new RAID level disk, and address information of occupied space of each disk in the system.

11. The apparatus of claim 10, further comprising a read and write unit to, when a transfer of data on the current RAID level disk is not complete,

when reading the service data, inquiring whether the current RAID level disk contains the service data, and if so, reading the service data; if the service data is not contained, reading the service data from the new RAID level disk according to the mapping association relationship established by the level conversion unit;

when the service data is written in, judging whether the new RAID level disk comprises enough space for writing in the service data according to the initial address and the length of the written service data, and when the space for writing in the service data is enough, writing in the service data and updating the address information occupied by the new RAID level disk of the recording unit and the address mapping incidence relation established by the level conversion unit; and when the space for writing the service data is not contained enough, the service data writing failure is fed back.

12. The apparatus according to any one of claims 7 to 9, wherein the mapping association specifically includes:

and the incidence relation of the initial addresses of the spaces of the current RAID level and the new RAID level in each disk in the system.