CN113986128B - LUN data replication method and device - Google Patents

Abstract

The application provides a LUN data copying method and device, which are applied to storage equipment. The storage device comprises a source LUN corresponding to a buffer zone, wherein the buffer zone is used for storing data records of data to be copied in the source LUN and partial data to be copied, and the data records comprise corresponding logical address segments of the data to be copied in the source LUN and storage positions of the data to be copied in the buffer zone. For each data record in the buffer zone, if the storage position included in the data record is empty, indicating that the data record corresponds to the data to be copied and is located in the source LUN, copying the corresponding data from the source LUN to the target LUN; if the data record includes a storage location that is not empty, indicating that the data record corresponds to the data to be copied in the buffer, copying the corresponding data from the buffer to the target LUN. The application can effectively reduce the data loss under abnormal conditions and effectively improve the utilization rate of the buffer area.

Description

LUN data replication method and device

Technical Field

The present application relates to the field of storage technology, and in particular to a LUN data replication method and device.

Background technique

Storage devices generally have data protection features, among which data replication, as a technology that can achieve data protection, has been widely used in storage devices.

At present, for data replication of logical unit numbers (English: Logical Unit Number, abbreviated: LUN) in storage devices, a periodic replication method is mainly used, that is, the newly written data in the source LUN is copied to the target LUN every preset replication period (for example, 1 hour). Here, the LUN to be copied in the storage device is called the source LUN; the LUN used to back up (copy) the data in the source LUN is called the target LUN.

If the source LUN fails during use, the target LUN will only store the data in the source LUN at the start of the last replication, resulting in the loss of data newly written to the source LUN since the last replication. The longer the replication cycle, the more data will be lost.

Summary of the invention

In view of this, the present application proposes a LUN data replication method and device to minimize data loss.

In order to achieve the above application purpose, this application provides the following technical solutions:

In a first aspect, the present application provides a LUN data replication method, which is applied to a storage device, wherein the storage device includes a source LUN to be replicated, the source LUN corresponds to a buffer zone, the buffer zone is used to store data records of the data to be replicated in the source LUN and part of the data to be replicated, the data records include a logical address segment corresponding to the data to be replicated in the source LUN and a storage position of the data to be replicated in the buffer zone, the source LUN also corresponds to a target LUN for replicating the data corresponding to the source LUN, and the method includes:

According to the order in which the data records are written, the data records in the buffer are traversed in sequence, and the following copy operation is performed for each data record:

If the storage location included in the data record is empty, obtaining the logical address segment included in the data record, and copying the data corresponding to the logical address segment in the source LUN to the target LUN;

If the storage location included in the data record is not empty, the data corresponding to the storage location in the buffer is copied to the target LUN.

Optionally, after copying the data corresponding to the logical address segment in the source LUN to the target LUN, the method further includes:

Delete the data record;

After copying the data corresponding to the storage location in the buffer to the target LUN, the method further includes:

Deleting the data corresponding to the storage position in the buffer;

Delete the data record.

Optionally, before traversing each data record in the buffer, the method further includes:

Receiving a write command for the source LUN, the write command including an address segment to be written and data to be written;

Traverse the existing data records in the buffer and perform the following maintenance operations for each data record:

If the storage location included in the data record is not empty, end the maintenance of the data record;

If the storage location included in the data record is empty, and the logical address segment included in the data record does not have an intersection with the address segment to be written, the maintenance of the data record is terminated;

If the storage location included in the data record is empty, and the logical address segment included in the data record has an intersection with the address segment to be written, read the data corresponding to the logical address segment from the source LUN and write it into the buffer, and update the storage location included in the data record to the storage location of the data corresponding to the logical address segment in the buffer;

After completing the maintenance of the existing data records, writing the data to be written into the address segment to be written in the source LUN;

A new data record is added to the buffer, wherein the logical address segment included in the new data record is the address segment to be written, and the storage location included in the new data record is empty.

Optionally, the source LUN is divided into a plurality of logical blocks according to a preset logical block size, the source LUN further corresponds to a difference bitmap, the difference bitmap includes a difference bit corresponding to each logical block, and the value of the difference bit is used to identify whether the logical block corresponding to the difference bit is written with the data to be copied, and the method further includes:

If the buffer is full, stop copying data according to the data records in the buffer, and stop maintaining the data records in the buffer;

If a write command for the source LUN is received, determining at least one to-be-written logical block involved in the write command, and writing the to-be-written data carried by the write command into each to-be-written logical block;

Updating the difference bit value corresponding to each to-be-written logical block in the difference bitmap to a target value, where the target value is used to identify the to-be-copied data that has been written into the logical block;

Traverse each data record in the buffer and perform the following update operation for each data record:

Determine at least one target logical block involved in the logical address segment included in the data record;

Update the value of the difference bit corresponding to each target logic block in the difference bitmap to the target value;

If the storage location included in the data record is not empty, deleting the data corresponding to the storage location in the buffer;

Delete the data record;

After completing the update operation for all data records, stop updating the difference bitmap, and generate a replication view of the source LUN, where the replication view includes the data at the current moment in the source LUN;

For each target difference bit in the difference bitmap whose value is a target value, data in a logical block corresponding to the target difference bit in the replication view is replicated to the target LUN.

Optionally, the method further includes:

After completing the update operation for all data records, restarting the maintenance of the data records in the buffer;

After completing the data replication based on the difference bitmap, restarting the data replication based on the data records in the buffer.

In a second aspect, the present application provides a LUN data replication device, which is applied to a storage device, wherein the storage device includes a source LUN to be replicated, the source LUN corresponds to a buffer zone, the buffer zone is used to store data records of the data to be replicated in the source LUN and part of the data to be replicated, the data records include a logical address segment corresponding to the data to be replicated in the source LUN and a storage position of the data to be replicated in the buffer zone, the source LUN also corresponds to a target LUN for replicating the data corresponding to the source LUN, and the device includes:

A traversal unit, used to traverse each data record in the buffer in sequence according to the order in which the data records are written;

The replication unit is used for obtaining the logical address segment included in each data record if the storage location included in the data record is empty, and copying the data corresponding to the logical address segment in the source LUN to the target LUN; if the storage location included in the data record is not empty, copying the data corresponding to the storage location in the buffer to the target LUN.

Optionally, after the copying unit copies the data corresponding to the logical address segment in the source LUN to the target LUN, the device further includes:

A deletion unit, used to delete the data record;

After the copying unit copies the data corresponding to the storage location in the buffer to the target LUN, the device further includes:

The deleting unit is used to delete the data corresponding to the storage position in the buffer; and delete the data record.

Optionally, before the traversal unit traverses each data record in the buffer, the device further includes:

A receiving unit, configured to receive a write command for the source LUN, the write command including an address segment to be written and data to be written;

The traversal unit is used to traverse the existing data records in the buffer;

A maintenance unit is used for, for each data record, if the storage location included in the data record is not empty, terminating the maintenance of the data record; if the storage location included in the data record is empty, and the logical address segment included in the data record does not have an intersection with the address segment to be written, terminating the maintenance of the data record; if the storage location included in the data record is empty, and the logical address segment included in the data record does have an intersection with the address segment to be written, reading the data corresponding to the logical address segment from the source LUN and writing it into the buffer, and updating the storage location included in the data record to be the storage location of the data corresponding to the logical address segment in the buffer;

A writing unit, configured to write the data to be written into the address segment to be written in the source LUN after completing the maintenance of the existing data record;

The maintenance unit is further used to add a new data record in the buffer, wherein the logical address segment included in the new data record is the address segment to be written, and the storage location included in the new data record is empty.

Optionally, the source LUN is divided into a plurality of logical blocks according to a preset logical block size, the source LUN further corresponds to a difference bitmap, the difference bitmap includes a difference bit corresponding to each logical block, and the value of the difference bit is used to identify whether the logical block corresponding to the difference bit is written with the data to be copied, and the device further includes:

A stopping unit, configured to stop copying data according to the data records in the buffer and stop maintaining the data records in the buffer if the buffer is full;

a determination unit, configured to, if receiving a write command for the source LUN, determine at least one to-be-written logical block involved in the write command, and write the to-be-written data carried by the write command into each to-be-written logical block;

An updating unit, used for updating the difference bit value corresponding to each to-be-written logical block in the difference bitmap to a target value, wherein the target value is used for identifying the to-be-copied data that has been written into the logical block;

The traversal unit is used to traverse each data record in the buffer;

The determining unit is further configured to determine, for each data record, at least one target logical block involved in a logical address segment included in the data record;

The updating unit is further used to update the value of the difference bit corresponding to each target logic block in the difference bitmap to the target value;

A deleting unit, configured to delete the data corresponding to the storage location in the buffer if the storage location included in the data record is not empty; and delete the data record;

A generating unit, configured to stop updating the difference bitmap after completing the update operation for all data records, and generate a replication view of the source LUN, wherein the replication view includes the data at the current moment in the source LUN;

The replication unit is further configured to replicate, for each target difference bit in the difference bitmap whose value is a target value, data in a logical block corresponding to the target difference bit in the replication view to the target LUN.

Optionally, the device further comprises:

A restart unit, used to restart the maintenance of the data records in the buffer after completing the update operation on all data records;

The restart unit is further configured to restart the data replication based on the data records in the buffer after completing the data replication based on the difference bitmap.

It can be seen from the above description that in the embodiment of the present application, the storage device maintains a buffer corresponding to the active LUN, and the buffer stores data records of the data to be copied and part of the data to be copied. For each data record in the buffer, if the storage location included in the data record is empty, it means that the data to be copied corresponding to the data record is located in the source LUN, and the corresponding data is copied from the source LUN to the target LUN according to the logical address segment included in the data record; if the storage location included in the data record is not empty, it means that the data to be copied corresponding to the data record is located in the buffer, and the corresponding data is copied from the buffer to the target LUN according to the storage location included in the data record. It can be seen that the embodiment of the present application continuously traverses the data records in the buffer, and copies the data to be copied corresponding to each data record to the target LUN in the order of data writing, so that the target LUN can store as much data as possible in the source LUN in time, so that even if the source LUN fails, the data copied to the target LUN is available, and not too much data will be lost; in addition, since the buffer only stores part (as little as possible) of the data to be copied, its space utilization is high, and more data records can be stored, further reducing the risk of data loss.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

FIG1 is a flow chart of a LUN data replication method shown in an embodiment of the present application;

FIG2 is a data record maintenance process shown in an embodiment of the present application;

FIG3 is another data replication process shown in an embodiment of the present application;

FIG. 4 is a schematic diagram of the structure of a LUN data replication device according to an embodiment of the present application.

Detailed ways

Here, exemplary embodiments are described in detail, and examples thereof are shown in the accompanying drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The implementations described in the following exemplary embodiments do not represent all implementations consistent with the present application.

The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to limit the embodiments of the present application. The singular forms of "a", "said" and "the" used in the embodiments of the present application are also intended to include plural forms, unless the context clearly indicates other meanings. It should also be understood that the term "and/or" used in this article refers to and includes any or all possible combinations of one or more associated listed items.

It should be understood that although the terms first, second, third, etc. may be used to describe various information in the embodiments of the present application, such information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of the embodiments of the present application, the negotiation information may also be referred to as the second information, and similarly, the second information may also be referred to as the negotiation information. Depending on the context, the word "if" as used herein may be interpreted as "at" or "when" or "in response to determination".

In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the embodiments of the present application are described in detail below in conjunction with the accompanying drawings and specific embodiments:

Referring to Fig. 1, it is a flow chart of a LUN data replication method shown in an embodiment of the present application. The flow chart is applied to a storage device.

The storage device includes a source LUN to be copied and a buffer corresponding to the source LUN. The buffer is used to store data records of the data to be copied in the source LUN and part of the data to be copied, wherein the data record includes a logical address segment corresponding to the data to be copied in the source LUN and a storage location of the data to be copied in the buffer. Here, the logical address segment is the storage location of the data to be copied in the source LUN.

In addition, the source LUN also corresponds to a target LUN for copying the data in the source LUN. The target LUN can be located in the storage device where the source LUN is located, or in other storage devices except the storage device where the source LUN is located, so as to improve data availability.

As shown in Figure 1, the process may include the following steps:

Step 101, traverse the data records in the buffer in sequence according to the order in which the data records are written.

Here, it should be noted that each data record corresponds to a write operation on the source LUN, so the writing order of the data records is the data writing order.

This step traverses each data record in sequence according to the order in which the data is written to ensure data timing.

For each data record, perform the following copy operations:

Step 102: If the storage location included in the data record is empty, obtain the logical address segment included in the data record, and copy the data corresponding to the logical address segment in the source LUN to the target LUN.

Here, the storage location included in the data record is empty, indicating that the data to be copied corresponding to the data record is not in the buffer but is located in the source LUN. At this time, the logical address segment included in the data record can be obtained. The logical address segment is the storage location of the data to be copied in the source LUN. The corresponding data is obtained from the logical address segment in the source LUN and copied to the target LUN.

Step 103: If the storage location included in the data record is not empty, copy the data corresponding to the storage location in the buffer to the target LUN.

Here, if the storage location included in the data record is not empty, it means that the data to be copied corresponding to the data record is located in the buffer. Then, directly according to the storage location included in the data record, the corresponding data is obtained from the storage location in the buffer and copied to the target LUN.

At this point, the process shown in Figure 1 is completed.

It can be seen from the process shown in Figure 1 that the embodiment of the present application continuously traverses the data records in the buffer and copies the data to be copied corresponding to each data record to the target LUN in the order in which the data is written, so that the target LUN can store as much data as possible in the source LUN in time. In this way, even if the source LUN fails, the data copied to the target LUN is available and not too much data will be lost. In addition, since the buffer only stores part (as little as possible) of the data to be copied, its space utilization rate is higher and more data records can be stored. The data corresponding to these data records will all be copied to the target LUN, thereby further reducing the risk of data loss.

Here, it should be noted that after completing the data copying for the current data record through step 102, the data record can be deleted to release the space in the buffer. Similarly, after completing the data copying for the current data record through step 103, the data corresponding to the data record in the buffer can be deleted, and the data record can be deleted.

The following describes the process of maintaining each data record in the storage device buffer. Referring to FIG2 , a data record maintenance process is shown in an embodiment of the present application.

As shown in FIG2 , the process may include the following steps:

Step 201: Receive a write command for a source LUN.

The write command includes data to be written into the source LUN (hereinafter referred to as data to be written) and a writing position of the data to be written into the source LUN (hereinafter referred to as address segment to be written).

Step 202, traverse the existing data records in the buffer.

Perform maintenance operations from step 203 to step 205 for each existing data record:

Step 203: If the storage location included in the data record is not empty, the maintenance of the data record is terminated.

If the storage location included in the data record is not empty, it means that the data to be copied corresponding to the data record has been written into the buffer due to an address conflict with the later written data in the source LUN, that is, it is ensured that the data previously written to the source LUN but not yet copied is not overwritten. The embodiment of the present application is no longer updated based on the write command for the data record whose storage location is not empty.

Step 204: If the storage location included in the data record is empty, and the logical address segment included in the data record does not intersect with the address segment to be written, the maintenance of the data record is terminated.

If the storage location included in the data record is empty, it means that the data to be copied corresponding to the data record is located in the source LUN. If the logical address segment corresponding to the data to be copied in the source LUN does not have an intersection with the address segment to be written included in the write command, it means that the current write command will not overwrite the data corresponding to the logical address segment in the source LUN. In other words, the current write command does not involve the operation of the logical address segment in the source LUN, so the processing of the current data record can be ended and the next data record can be traversed.

Step 205, if the storage location included in the data record is empty, and the logical address segment included in the data record has an intersection with the address segment to be written, read the data corresponding to the logical address segment from the source LUN and write it into the buffer, and update the storage location included in the data record to the storage location of the data corresponding to the logical address segment in the buffer.

If the storage location included in the data record is empty, it means that the data to be copied corresponding to the data record is located in the source LUN. If the logical address segment corresponding to the data to be copied in the source LUN intersects with the address segment to be written included in the write command, it means that the current write command will cause the data corresponding to the logical address segment in the source LUN to be overwritten. In order to avoid overwriting of data that has not yet been copied in the source LUN, the embodiment of the present application writes the data corresponding to the logical address segment in the source LUN into the buffer, and updates the storage location included in the current data record to the location where the data corresponding to the logical address segment is written into the buffer.

Step 206, after completing the maintenance of the existing data records, write the data to be written into the address segment to be written in the source LUN.

That is, the write operation to the source LUN is completed.

Step 207, adding a new data record in the buffer, wherein the logical address segment included in the new data record is the address segment to be written, and the storage location included in the new data record is empty.

That is, a data record corresponding to the current write command is added, and the data corresponding to the data record is located in the source LUN.

At this point, the process shown in Figure 2 is completed.

It can be seen from the process shown in FIG. 2 that in the embodiment of the present application, a corresponding data record is generated for each write command. When a new write command causes the existing uncopied data in the source LUN to be overwritten, the existing uncopied data is copied to the buffer, and then the data corresponding to the write command is written to the source LUN. In short, in the present application, the source LUN always stores the latest data, and the existing uncopied data is stored in the buffer, thereby ensuring the timing of subsequent data replication.

Although the present application only stores part of the data to be copied in the buffer, the buffer may still be full. When the buffer is full, it means that the current speed of writing data to the source LUN is significantly higher than the speed of copying data to the target LUN. At this time, the process shown in Figure 3 can be executed.

Referring to FIG. 3 , another data replication process flow is shown in an embodiment of the present application.

As shown in FIG3 , the process may include the following steps:

Step 301: If the buffer is full, stop copying data according to the data records in the buffer, and stop maintaining the data records in the buffer.

That is, the process shown in FIG. 1 and FIG. 2 is stopped.

Step 302: If a write command for a source LUN is received, determine at least one to-be-written logical block involved in the write command, and write the data carried by the write command into each to-be-written logical block.

Here, the source LUN may be divided into a plurality of logical blocks according to a preset logical block size (eg, 8 KB), such as [0, 8 KB], [8 KB, 16 KB], [16 KB, 24 KB], and so on.

When a write command is received, the address range to be written included in the write command is obtained, and then, based on the address range to be written, the logical blocks involved in the address range to be written are determined, that is, the logical blocks of data to be written (hereinafter referred to as logical blocks to be written). For example, if the address range to be written is [10KB, 20KB], then the logical blocks to be written are determined to be [8KB, 16KB] and [16KB, 24KB] based on the address range to be written.

The data to be written carried by the write command is written into each logical block to be written according to the corresponding address range to be written.

Step 303: Update the value of the difference bit corresponding to each to-be-written logical block in the difference bitmap to the target value.

Here, it should be noted that the difference bitmap includes difference bits corresponding to each logic block in the source LUN. The value of each difference bit is used to identify whether the logic block corresponding to the difference bit has been written with the data to be copied.

After the storage device writes new data to the source LUN through step 302, it is necessary to update the difference bits corresponding to each logical block to be written in the difference bitmap, and update the value of the difference bit to the target value. Here, the target value is used to identify that the data to be copied has been written in the logical block, for example, the target value is "1". On the contrary, when the value of the difference bit is "0", it means that the data to be copied has not been written in the logical block, that is, no new data has been written in the logical block.

Step 304, traverse each data record in the buffer.

In the embodiment of the present application, in addition to maintaining the difference bitmap according to the write command, it is also necessary to update the value of the corresponding difference bit in the difference bitmap according to each data record in the buffer.

Specifically, step 305 to step 308 are executed for each data record.

Step 305: Determine at least one target logical block involved in the logical address segment included in the data record.

For example, if the logical address segment included in the data record is [5KB, 15KB], then the logical blocks involved in the logical address segment (hereinafter referred to as target logical blocks) include [0, 8KB] and [8KB, 16KB].

Step 306: Update the value of the difference bit corresponding to each target logic block in the difference bitmap to the target value.

Since the data in the logical address segment corresponding to the data record has not yet been copied to the target LUN, that is, there is data that has not been copied to the target LUN in each target logical block corresponding to the logical address segment, therefore, this step updates the value of the difference bit corresponding to each target logical block in the difference bitmap to the target value to identify that there is data to be copied in each target logical block.

Step 307: If the storage location included in the data record is not empty, delete the data corresponding to the storage location in the buffer.

After updating the difference bitmap according to the current data record, if the storage location included in the data record is not empty, it means that the buffer still contains the corresponding data of the data record, and the data can be deleted. This is because the source LUN already contains the latest data, and when the copy speed is significantly lower than the new data writing speed, it is not necessary to continue copying according to the data sequence.

Step 308: Delete the data record.

At this point, the update operation based on a data record in the buffer is completed.

Step 309: After completing the update operation for all data records in the buffer, stop updating the difference bitmap, and generate a copy view of the source LUN, the copy view including the data in the source LUN at the current moment.

After all data records in the buffer are updated to the difference bitmap, the difference bitmap can be used for a new replication, and no new differences need to be recorded. At the same time, a replication view on the source LUN needs to be generated. The replication view can be a snapshot, and the data of the source LUN at the current moment can be obtained through the replication view.

Step 310: For each target difference bit in the difference bitmap whose value is the target value, copy the data in the logical block corresponding to the target difference bit in the replication view to the target LUN.

Here, the difference bit whose value is the target value is called the target difference bit. It is understandable that the target difference bit is named only for the convenience of distinction and is not used for limitation.

The data in the logical blocks corresponding to the target difference bits are the data to be copied. Therefore, this step copies the data in the logical blocks corresponding to each target difference bit in the replication view to the target LUN to speed up the consistency of the data in the target LUN with the data in the source LUN. More precisely, it makes the data in the target LUN consistent with the data in the source LUN (the data in the replication view) when the replication starts.

At this point, the process shown in Figure 3 is completed.

It can be seen from the process shown in FIG3 that in the embodiment of the present application, when the buffer is full, the difference bitmap is updated according to the newly received write command and the existing data records in the buffer to identify the logical blocks in the source LUN that need to be copied. For each logical block that needs to be copied, the data corresponding to the logical block in the source LUN at the time of starting the copy is copied from the copy view to the target LUN, so that the data in the target LUN and the data in the source LUN are kept in the same time plane, ensuring that the data in the target LUN is available.

In addition, it should be noted that after completing the update operation for all data records in the buffer, all the space in the buffer is released. At this time, the maintenance of the data records in the buffer can be restarted, that is, executing the process shown in Figure 2, and continuing to generate corresponding data records according to the write command and write them into the buffer.

After completing the data replication based on the difference bitmap (step 310), the data replication based on the data records in the buffer may be restarted, that is, the process shown in FIG. 1 is executed to resume data replication according to the data sequence.

It can be seen that in the embodiment of the present application, when the buffer is not full, continuous data replication is achieved by continuously traversing the data records in the buffer, so that the target LUN can synchronize the data in the source LUN in time, and narrow the gap between the data in the target LUN and the data in the source LUN, so that data loss can be reduced when the source LUN fails; and when the buffer is full, by converting all data records in the buffer into a differential bitmap format, the storage device directly synchronizes the changed data in the source LUN to the target LUN according to the differential bitmap and the replication view, so that the data in the target LUN and the data in the source LUN remain on the same time plane, ensuring that the data in the target LUN is available.

The method provided in the embodiment of the present application is described above. The device provided in the embodiment of the present application is described below:

Referring to FIG4 , a schematic diagram of the structure of the apparatus provided in an embodiment of the present application is applied to a storage device. The storage device includes a source LUN to be copied, the source LUN corresponds to a buffer zone, the buffer zone is used to store data records of the data to be copied in the source LUN and part of the data to be copied, the data records include the logical address segment corresponding to the data to be copied in the source LUN and the storage location of the data to be copied in the buffer zone, the source LUN also corresponds to a target LUN for copying the data corresponding to the source LUN, and the apparatus includes:

A traversal unit 401 is used to traverse the data records in the buffer in sequence according to the order in which the data records are written;

The copying unit 402 is used to obtain the logical address segment included in each data record if the storage location included in the data record is empty, and copy the data corresponding to the logical address segment in the source LUN to the target LUN; if the storage location included in the data record is not empty, copy the data corresponding to the storage location in the buffer to the target LUN.

As an embodiment, after the copying unit 402 copies the data corresponding to the logical address segment in the source LUN to the target LUN, the device further includes:

A deletion unit, used to delete the data record;

After the copy unit 402 copies the data corresponding to the storage location in the buffer to the target LUN, the device further includes:

The deleting unit is used to delete the data corresponding to the storage position in the buffer; and delete the data record.

As an embodiment, before the traversal unit 401 traverses each data record in the buffer, the device further includes:

A receiving unit, configured to receive a write command for the source LUN, the write command including an address segment to be written and data to be written;

The traversal unit 401 is used to traverse the existing data records in the buffer;

A maintenance unit is used for, for each data record, if the storage location included in the data record is not empty, terminating the maintenance of the data record; if the storage location included in the data record is empty, and the logical address segment included in the data record does not have an intersection with the address segment to be written, terminating the maintenance of the data record; if the storage location included in the data record is empty, and the logical address segment included in the data record does have an intersection with the address segment to be written, reading the data corresponding to the logical address segment from the source LUN and writing it into the buffer, and updating the storage location included in the data record to be the storage location of the data corresponding to the logical address segment in the buffer;

A writing unit, configured to write the data to be written into the address segment to be written in the source LUN after completing the maintenance of the existing data record;

The maintenance unit is further used to add a new data record in the buffer, wherein the logical address segment included in the new data record is the address segment to be written, and the storage location included in the new data record is empty.

As an embodiment, the source LUN is divided into a plurality of logical blocks according to a preset logical block size, the source LUN further corresponds to a difference bitmap, the difference bitmap includes a difference bit corresponding to each logical block, and the value of the difference bit is used to identify whether the logical block corresponding to the difference bit is written with the data to be copied, and the device further includes:

A stopping unit, configured to stop copying data according to the data records in the buffer and stop maintaining the data records in the buffer if the buffer is full;

a determination unit, configured to, if receiving a write command for the source LUN, determine at least one to-be-written logical block involved in the write command, and write the to-be-written data carried by the write command into each to-be-written logical block;

An updating unit, used for updating the difference bit value corresponding to each to-be-written logical block in the difference bitmap to a target value, wherein the target value is used for identifying the to-be-copied data that has been written into the logical block;

The traversal unit 401 is used to traverse each data record in the buffer;

The determining unit is further configured to determine, for each data record, at least one target logical block involved in a logical address segment included in the data record;

The updating unit is further used to update the value of the difference bit corresponding to each target logic block in the difference bitmap to the target value;

A deleting unit, configured to delete the data corresponding to the storage location in the buffer if the storage location included in the data record is not empty; and delete the data record;

A generating unit, configured to stop updating the difference bitmap after completing the update operation for all data records, and generate a replication view of the source LUN, wherein the replication view includes the data at the current moment in the source LUN;

The replication unit 402 is further configured to replicate, for each target difference bit in the difference bitmap whose value is a target value, data in a logical block corresponding to the target difference bit in the replication view to the target LUN.

As an embodiment, the device further includes:

A restart unit, used to restart the maintenance of the data records in the buffer after completing the update operation on all data records;

The restart unit is further configured to restart the data replication based on the data records in the buffer after completing the data replication based on the difference bitmap.

At this point, the description of the device shown in FIG. 4 is completed.

It can be seen from the above description that in the embodiment of the present application, the storage device maintains a buffer corresponding to the active LUN, and the buffer stores data records of the data to be copied and part of the data to be copied. For each data record in the buffer, if the storage location included in the data record is empty, it means that the data to be copied corresponding to the data record is located in the source LUN, and the corresponding data is copied from the source LUN to the target LUN according to the logical address segment included in the data record; if the storage location included in the data record is not empty, it means that the data to be copied corresponding to the data record is located in the buffer, and the corresponding data is copied from the buffer to the target LUN according to the storage location included in the data record. It can be seen that the embodiment of the present application continuously traverses the data records in the buffer, and copies the data to be copied corresponding to each data record to the target LUN in the order of data writing, so that the target LUN can store as much data as possible in the source LUN in time, so that even if the source LUN fails, the data copied to the target LUN is available, and not too much data will be lost; in addition, since the buffer only stores part (as little as possible) of the data to be copied, its space utilization is high, and more data records can be stored, further reducing the risk of data loss.

The above description is only a preferred embodiment of the embodiments of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the embodiments of the present application should be included in the scope of protection of the present application.

Claims (8)

1. A LUN data replication method, characterized in that it is applied to a storage device, the storage device includes a source LUN to be replicated, the source LUN corresponds to a buffer zone, the buffer zone is used to store data records of the data to be replicated in the source LUN and part of the data to be replicated, the data records include a logical address segment corresponding to the data to be replicated in the source LUN and a storage location of the data to be replicated in the buffer zone, the source LUN also corresponds to a target LUN for replicating the data corresponding to the source LUN, the method comprises: Receiving a write command for the source LUN, the write command including an address segment to be written and data to be written; Traverse the existing data records in the buffer and perform the following maintenance operations for each data record: If the storage location included in the data record is not empty, end the maintenance of the data record; If the storage location included in the data record is empty, and the logical address segment included in the data record does not have an intersection with the address segment to be written, the maintenance of the data record is terminated; If the storage location included in the data record is empty, and the logical address segment included in the data record has an intersection with the address segment to be written, read the data corresponding to the logical address segment from the source LUN and write it into the buffer, and update the storage location included in the data record to the storage location of the data corresponding to the logical address segment in the buffer; After completing the maintenance of the existing data records, writing the data to be written into the address segment to be written in the source LUN; Adding a new data record in the buffer, wherein the logical address segment included in the new data record is the address segment to be written, and the storage location included in the new data record is empty; According to the order in which the data records are written, the data records in the buffer are traversed in sequence, and the following copy operation is performed for each data record: If the storage location included in the data record is empty, obtaining the logical address segment included in the data record, and copying the data corresponding to the logical address segment in the source LUN to the target LUN; If the storage location included in the data record is not empty, the data corresponding to the storage location in the buffer is copied to the target LUN. 2. The method according to claim 1, characterized in that after copying the data corresponding to the logical address segment in the source LUN to the target LUN, the method further comprises: Delete the data record; After copying the data corresponding to the storage location in the buffer to the target LUN, the method further includes: Deleting the data corresponding to the storage position in the buffer; Delete the data record. 3. The method according to claim 1, wherein the source LUN is divided into a plurality of logical blocks according to a preset logical block size, the source LUN further corresponds to a difference bitmap, the difference bitmap includes a difference bit corresponding to each logical block, and the value of the difference bit is used to identify whether the logical block corresponding to the difference bit is written with the data to be copied, and the method further comprises: If the buffer is full, stop copying data according to the data records in the buffer, and stop maintaining the data records in the buffer; If a write command for the source LUN is received, determining at least one to-be-written logical block involved in the write command, and writing the to-be-written data carried by the write command into each to-be-written logical block; Updating the difference bit value corresponding to each to-be-written logical block in the difference bitmap to a target value, where the target value is used to identify the to-be-copied data that has been written into the logical block; Traverse each data record in the buffer and perform the following update operation for each data record: Determine at least one target logical block involved in the logical address segment included in the data record; Update the value of the difference bit corresponding to each target logic block in the difference bitmap to the target value; If the storage location included in the data record is not empty, deleting the data corresponding to the storage location in the buffer; Delete the data record; After completing the update operation for all data records, stop updating the difference bitmap, and generate a replication view of the source LUN, where the replication view includes the data at the current moment in the source LUN; For each target difference bit in the difference bitmap whose value is a target value, data in a logical block corresponding to the target difference bit in the replication view is replicated to the target LUN. 4. The method according to claim 3, characterized in that the method further comprises: After completing the update operation for all data records, restarting the maintenance of the data records in the buffer; After completing the data replication based on the difference bitmap, restarting the data replication based on the data records in the buffer. 5. A LUN data replication device, characterized in that it is applied to a storage device, the storage device includes a source LUN to be replicated, the source LUN corresponds to a buffer zone, the buffer zone is used to store data records of the data to be replicated in the source LUN and part of the data to be replicated, the data records include a logical address segment corresponding to the data to be replicated in the source LUN and a storage location of the data to be replicated in the buffer zone, the source LUN also corresponds to a target LUN for replicating the data corresponding to the source LUN, the device includes: A receiving unit, configured to receive a write command for the source LUN, the write command including an address segment to be written and data to be written; A traversal unit, used for traversing existing data records in the buffer; A maintenance unit is used for, for each data record, if the storage location included in the data record is not empty, terminating the maintenance of the data record; if the storage location included in the data record is empty, and the logical address segment included in the data record does not have an intersection with the address segment to be written, terminating the maintenance of the data record; if the storage location included in the data record is empty, and the logical address segment included in the data record does have an intersection with the address segment to be written, reading the data corresponding to the logical address segment from the source LUN and writing it into the buffer, and updating the storage location included in the data record to be the storage location of the data corresponding to the logical address segment in the buffer; A writing unit, configured to write the data to be written into the address segment to be written in the source LUN after completing the maintenance of the existing data record; The maintenance unit is further used to add a new data record in the buffer, the logical address segment included in the new data record is the address segment to be written, and the storage location included in the new data record is empty; The traversal unit is further used to traverse the data records in the buffer in sequence according to the order in which the data records are written; The replication unit is used for obtaining the logical address segment included in each data record if the storage location included in the data record is empty, and copying the data corresponding to the logical address segment in the source LUN to the target LUN; if the storage location included in the data record is not empty, copying the data corresponding to the storage location in the buffer to the target LUN. 6. The device according to claim 5, characterized in that after the copying unit copies the data corresponding to the logical address segment in the source LUN to the target LUN, the device further comprises: A deletion unit, used to delete the data record; After the copy unit copies the data corresponding to the storage location in the buffer to the target LUN, the device further includes: The deleting unit is used to delete the data corresponding to the storage position in the buffer; and delete the data record. 7. The device according to claim 5, wherein the source LUN is divided into a plurality of logical blocks according to a preset logical block size, the source LUN further corresponds to a difference bitmap, the difference bitmap includes a difference bit corresponding to each logical block, the value of the difference bit is used to identify whether the logical block corresponding to the difference bit is written with the data to be copied, and the device further comprises: A stopping unit, configured to stop copying data according to the data records in the buffer and stop maintaining the data records in the buffer if the buffer is full; a determination unit, configured to, if receiving a write command for the source LUN, determine at least one to-be-written logical block involved in the write command, and write the to-be-written data carried by the write command into each to-be-written logical block; An updating unit, used for updating the difference bit value corresponding to each to-be-written logical block in the difference bitmap to a target value, wherein the target value is used for identifying the to-be-copied data that has been written into the logical block; The traversal unit is used to traverse each data record in the buffer; The determining unit is further configured to determine, for each data record, at least one target logical block involved in a logical address segment included in the data record; The updating unit is further used to update the value of the difference bit corresponding to each target logic block in the difference bitmap to the target value; A deleting unit, configured to delete the data corresponding to the storage location in the buffer if the storage location included in the data record is not empty; and delete the data record; A generating unit, configured to stop updating the difference bitmap after completing the update operation for all data records, and generate a replication view of the source LUN, wherein the replication view includes the data at the current moment in the source LUN; The replication unit is further configured to replicate, for each target difference bit in the difference bitmap whose value is a target value, data in a logical block corresponding to the target difference bit in the replication view to the target LUN. 8. The device according to claim 7, characterized in that the device further comprises: A restart unit, used to restart the maintenance of the data records in the buffer after completing the update operation on all data records; The restart unit is further configured to restart the data replication based on the data records in the buffer after completing the data replication based on the difference bitmap.