CN103605617B - The method and device that a kind of records store data changes - Google Patents

Abstract

The present application discloses a method and device for recording and storing data changes, wherein the method includes: determining the logical block area where the currently changed logical block in the logical unit number LUN is located; querying whether the logical block already exists in the bitmap set The corresponding bitmap of the area; if it does not exist, then set up the corresponding bitmap of the logical block area in the bitmap set, and record the change of the current change logical block in the corresponding bitmap; if it exists, then The change of the current changed logic block is directly recorded in the corresponding bitmap. Through the above method, the present application can reduce the storage resources occupied by the bitmap and reduce the waste of memory resources.

Description

A method and device for recording and storing data changes

technical field

The present application relates to the field of storage technology, in particular to a method and device for recording changes in stored data.

Background technique

In the prior art, a bitmap (Bitmap) technology is usually used to record whether data in a Logical Unit Number (Logic UnitNumber, LUN for short) changes. Specifically, apply for a fixed-capacity memory in the memory as a bitmap that records the changes of logical blocks (chunks) in the LUN, where the capacity required by the bitmap is determined by the maximum capacity of the LUN and the bits in the bitmap corresponding to The size of the logical block is jointly determined. For example, as shown in Figure 1, set one bit in the bitmap to record the data change in a logical block, the maximum capacity of the LUN is 64TB, and the size of each logical block in the LUN is 64KB, the required capacity is 1G bit When the bitmap of the LUN does not have any data changes, all bits in the bitmap are "0". When the data in the logical blocks chunk0, chunk1, chunk2, and Bits 1, 2, 3 and 9 are set to "1". Therefore, by determining the position of the bit whose value is 1 in the bitmap, it is possible to know which logical blocks in the LUN have data changes.

However, for the current diversified storage technologies, especially dynamically expandable storage technologies such as thin provisioning technology, the capacity of LUNs can be allocated on demand, and usually the actual capacity is much smaller than the maximum capacity. If the existing bitmap technology is still used, the following problems exist: the capacity of the bitmap is fixed, and if it is necessary to ensure that all logical blocks in the LUN are changed, the capacity of the bitmap must be determined according to the maximum supported capacity of the LUN. Application, rather than the actual capacity of the LUN, resulting in a waste of memory resources for the application. Moreover, a general system supports multiple LUNs. For example, in the case of supporting 1024 LUNs, according to the above example, each 1TB LUN needs to apply for a bitmap with a capacity of 1G bit, and a system needs a total of 1024*1G bit=1T bit Obviously, a bitmap that is only used to record changes also takes up a lot of memory resources. If the specification continues to increase, such a large memory requirement will be difficult for the storage system to support.

Contents of the invention

The technical problem mainly solved by this application is to provide a method and device for recording changes in stored data, which can reduce storage resources occupied by bitmaps and reduce waste of memory resources.

In order to solve the above technical problems, the first aspect of the present application provides a method for recording changes in stored data, the method includes the following steps: determining the logical block area where the currently changed logical block in the logical unit number LUN is located, wherein the logical The unit number LUN includes at least two logical block areas, and the logical block area includes a plurality of logical blocks; query whether the corresponding bitmap of the logical block area already exists in the bitmap set, wherein the bitmap set is used to place multiple bitmaps, each of which is used to record changes in the logical blocks corresponding to one of the logical block areas, and the corresponding bitmap of the logical block areas is the bit that records the changes in the logical blocks of the logical block area Figure; if it does not exist, then set up the corresponding bitmap of the logical block area in the bitmap set, and record the change in the current change logical block in the corresponding bitmap; if it exists, directly in the said corresponding bitmap The change of the current change logic block is recorded in the corresponding bitmap.

With reference to the first aspect, the first possible implementation manner of the first aspect of the present application is: before the step of querying whether the corresponding bitmap of the logical block area already exists in the bitmap set, the method further includes: adding the The storage data in the logical unit number LUN is divided into a plurality of logical blocks; the plurality of logical blocks are divided into a first number of logical block areas, wherein the first numerical value is at least 2; the number of each logical block area is determined Corresponding bitmap information, wherein, the corresponding bitmap information of the logical block area includes that the number of digits of the corresponding bitmap of the logical block area is equal to the number of logical blocks of the logical block area, and the corresponding bitmap of the logical block area Each bit of each corresponds to recording whether a logical block in the logical block area has changed, and each bit can be set as a first flag or a second flag, and the first flag is used to indicate that the bit corresponds to The logic block has changed, and the second flag is used to indicate that the logic block corresponding to the bit has not changed.

With reference to the first possible implementation manner of the first aspect, the second possible implementation manner of the first aspect of the present application is: the step of recording the change of the current changed logical block in the corresponding bitmap includes: according to The corresponding bitmap information of the logical block area, find out the bit in the corresponding bitmap for recording whether the current changed logical block has changed, and set the found bit as the first mark, and record the current The change time of the change logic block.

With reference to the second possible implementation manner of the first aspect, the third possible implementation manner of the first aspect of the present application is: the method further includes: when receiving the copy command, acquiring the preset time condition in the copy command ; Search out the bits in the bitmap whose time the logic block changes meets the preset time condition in the bitmap set; copy the logic block corresponding to the bit in the searched out bitmap, and After the copying is completed, set the bit in the searched bitmap as the second flag.

In combination with any of the first to third possible implementation manners of the first aspect, the fourth possible implementation manner of the first aspect of the present application is: the method further includes: detecting whether all bits in the bitmap set are If the bitmap of the second mark exists, the bitmap is deleted from the bitmap set.

In order to solve the above technical problems, the second aspect of the present application provides a device for recording changes in stored data. The device includes a determination module, a query module, an establishment module, and a recording module. The determination module is used to determine the logical unit number LUN Currently change the logical block area where the logical block is located, and send the determined logical block area to the query module, wherein the logical unit number LUN includes at least two logical block areas, and the logical block area includes multiple logical blocks ; The query module is used to query whether the corresponding bitmap of the logical block area already exists in the bitmap set, and sends the query result to the establishment module and the recording module, wherein the bitmap set is used to place multiple bitmaps , each of the bitmaps is used to record changes in the logical blocks corresponding to one of the logical block areas, and the corresponding bitmap of the logical block area is the bitmap that records the changes in the logical blocks of the logical block area; The establishment module is used to establish the corresponding bitmap of the logical block area in the bitmap set when the corresponding bitmap of the logical block area is not found, and send the corresponding bitmap to the recording module ; The recording module is used to record the change of the current change logic block in the corresponding bitmap.

With reference to the second aspect, the first possible implementation manner of the second aspect of the present application is: further comprising a division module, the division module is configured to divide the storage data in the logical unit number LUN into a plurality of logical blocks, and divide the The plurality of logical blocks are divided into a first number of logical block areas, the corresponding bitmap information of each logical block area is determined, and the corresponding bitmap information of each logical block area is sent to the recording module, wherein, The first numerical value is at least 2, the corresponding bitmap information of the logical block area includes the number of bits of the corresponding bitmap of the logical block area equal to the number of logical blocks of the logical block area, and the corresponding bitmap of the logical block area Each bit of the bitmap corresponds to recording whether a logical block of the logical block area has changed, and each bit can be set as a first flag or a second flag, and the first flag is used to represent the The corresponding logic block has changed, and the second flag is used to indicate that the logic block corresponding to the bit has not changed.

With reference to the first possible implementation manner of the second aspect, the second possible implementation manner of the second aspect of the present application is: the recording module is specifically configured to find out the Corresponding to the bit in the bitmap used to record whether the current changing logic block changes, and setting the found bit as the first flag, and recording the time when the current changing logic block changes.

With reference to the second possible implementation manner of the second aspect, the third possible implementation manner of the second aspect of the present application is: further comprising a copying module, the copying module is configured to obtain the According to the preset time condition, the bits in the bitmap whose time the logical block changes meet the preset time condition are searched in the bitmap set, and the logical block corresponding to the bit in the searched bitmap is searched Perform a copy operation, and set the bit in the searched bitmap as the second mark after the copy is completed.

In combination with any one of the first to third possible implementation manners of the second aspect, the fourth possible implementation manner of the second aspect of the present application is: further comprising a deletion module, the deletion module is used to detect whether there is All bits are the bitmap of the second mark, and if present, the bitmap is deleted from the bitmap set.

Through the above scheme, this application uses the bitmap set to record the changes of the storage data of the LUN, and only when the logic block changes, the corresponding bitmap of the logic block is established, which is different from the fixed use of a bitmap to record all the storage data of the LUN According to the prior art of changing situations, this application adopts a dynamic bitmap method, so that the total storage space occupied by the bitmap corresponds to the number of logical blocks that change in the LUN, realizing the on-demand allocation of bitmaps and reducing the storage resources occupied. At the same time, It also improves the utilization efficiency of the bitmap and reduces the waste of bitmap memory resources.

Description of drawings

FIG. 1 is a diagram of the corresponding relationship between logical blocks and bitmaps in a LUN in the prior art;

Fig. 2 is a flowchart of an embodiment of a method for recording and storing data changes in the present application;

Fig. 3 is a flow chart of another embodiment of the method for recording and storing data changes in the present application;

Fig. 4 is a flow chart of pre-setting logical block information and corresponding bitmap information of each logical block area in the method for recording storage data changes shown in Fig. 3;

Fig. 5 is a schematic structural diagram of a bit atlas in an implementation mode of asynchronous remote replication by a device for recording and storing data changes in the present application;

Fig. 6 is a schematic structural diagram of a bit atlas in an embodiment of synchronous remote replication of a device for recording and storing data changes in the present application;

FIG. 7 is a schematic structural diagram of an embodiment of a device for recording and storing data changes in the present application;

Fig. 8 is a schematic structural diagram of another embodiment of the device for recording and storing data changes in the present application;

Fig. 9 is a schematic structural diagram of another embodiment of the device for recording and storing data changes in the present application.

detailed description

The following description will be made in conjunction with the accompanying drawings and specific implementation manners.

Please refer to FIG. 2 . FIG. 2 is a flowchart of an embodiment of a method for recording and storing data changes in the present application. In this embodiment, the method includes the following steps:

Step S201: The device for recording changes in stored data determines the logical block area where the currently changed logical block is located in the LUN.

In this implementation manner, the LUN adopts thin provisioning (thin) technology, and the LUN can be dynamically expanded. Wherein, as a storage space, the LUN includes at least two logical block areas, and the logical block area includes a plurality of logical blocks, and each logical block is defined as storing data with a certain capacity. In this embodiment, each logical block in the LUN is assigned a different logical block number, and the logical block information of each logical block area is pre-stored locally. For example, the first logical block area includes logical blocks 0 and 1, and the logical block area of the second The second logical block area contains logical blocks 2 and 3...and so on. When a logical block in the LUN changes, the device for recording and storing data changes obtains the logical block number of the currently changed logical block in the LUN. The preset relationship between the logical block area and the logical block is that each logical block includes two logical blocks. block, determining the logical block area where the currently changed logical block is located.

Step S202: Query whether the corresponding bitmap of the logical block already exists in the bitmap set.

In this application, a change in storage data on a logical block in the LUN is a change in the logical block in the LUN. When the logical block in the LUN changes, the device for recording the change of stored data uses the bitmap set to record the change of the logical block in the LUN. The bitmap set can be stored in the storage medium in different data structures (such as tree structure, list). Optimally, the device can also temporarily store the bitmap set in the cache to speed up the processing of the bitmap space, and Regularly store the bitmap set data in the cache in permanent storage media, such as hard disk and flash. Specifically, the bitmap set is used to place a plurality of bitmaps, wherein each bitmap is used to record a change of a logical block corresponding to one of the logical block areas.

Specifically, the device is locally preset with corresponding bitmap information of each logical block in the LUN. When the logical block in the LUN changes, the device for recording and storing data changes obtains the corresponding bitmap information of the logical block area where the currently changed logical block is located according to the preset corresponding bitmap information, and queries whether the acquired bitmap is included in the bitmap set. Corresponding bitmap information, if not included, that is, there is no corresponding bitmap of the logical block area of the current changing logical block in the bitmap set, then step S203 is performed, if included, that is, the corresponding bitmap of the logical block area of the current changing logical block already exists in the bitmap set bitmap, execute step S204. Wherein, the corresponding bitmap of the logical block area is a bitmap that records changes of logical blocks in the logical block area.

For example, a LUN is divided into 16 logical block areas, and each logical block area includes 8 logical blocks. The device for recording and storing data changes presets the corresponding bitmap information of each logical block area as the corresponding bitmap of the first logical block area as the first bitmap, and the corresponding bitmap of the second logical block area as the second bitmap... ...and so on, and each bitmap includes 8 bits, and each bit is used to record whether a logical block has changed. Correspondingly, the first bitmap is used to record the first logical block area, that is, the 1st to 8th logical blocks, and the second bitmap is used to record the second logical block area, that is, the 9th to 16th logical blocks, and the second bitmap is used to record the second logical block area, that is, the 9th to 16th logical blocks. The three-bit map is correspondingly used to record the third logical block area, that is, the 17th to 24th logical blocks...and so on. When the 10th and 15th logical blocks in the LUN change, the device determines that the currently changed logical block is located in the second logical block area, and obtains the second logical block area according to the bitmap information corresponding to the preset logical block area The corresponding bitmap information of the two logical block areas is the second bitmap, and the device inquires whether the information of the bitmap established in the current bitmap set includes the second bitmap information, and if so, the second logical bitmap has been established in the bitmap set If the corresponding bitmap of the block area is not included, the corresponding bitmap of the second logical block area is not established in the bitmap set.

Step S203: Create a corresponding bitmap of the logical block area in the bitmap set, and record the change of the currently changed logical block in the corresponding bitmap.

If the corresponding bitmap of the logical block area where the currently changed logical block is located is not found in the bitmap set, the device for recording and storing data changes establishes the logical block area where the currently changed logical block is located in the bitmap set The corresponding bitmap of the corresponding bitmap, and the change of the current change logic block is recorded in the corresponding bitmap, for example, the bit corresponding to the current change logic block in the corresponding bitmap is set as the first mark to identify the logic block corresponding to the bit When the block changes, the bit corresponding to the logical block that has not changed in the corresponding bitmap is set as the second flag to identify that the logical block corresponding to the bit has not changed.

Step S204: Directly record the change of the current changed logic block in the corresponding bitmap.

If the corresponding bitmap of the logical block area where the currently changed logical block is located is found in the bitmap set, the device for recording the change of the stored data records the change of the current changed logical block in the corresponding bitmap, for example, The bit corresponding to the current changing logical block in the corresponding bitmap is set as the first mark to identify that the logical block corresponding to the bit has changed, and the bit corresponding to the logical block that has not changed in the corresponding bitmap is set as the second mark, To identify that the logic block corresponding to this bit has not changed.

In this embodiment, a bitmap set is used to record whether the logical blocks in the LUN have changed, and the LUN is divided into multiple logical block areas, one logical block area corresponds to a bitmap, and the bitmap generation conditions in the bitmap set are: When the logical block changes, the corresponding bitmap of the logical block area where the logical block is located is established, and there is no need to generate the corresponding bitmap of the logical block area that has not changed, realizing the allocation of bitmaps on demand and reducing the bitmap space At the same time, it also reduces the storage resources occupied by the total bitmap.

It should be noted that the LUN in this embodiment adopts the thin provisioning technology, but in other embodiments, the LUN can also adopt other technologies that can be dynamically expanded, or the LUN cannot be dynamically expanded, and its capacity is fixed. The specific type of the LUN does not affect the implementation of the method of the present application, so the LUN is not specifically limited here.

Please refer to FIG. 3 . FIG. 3 is a flow chart of another embodiment of the method for recording and storing data changes in the present application. In this embodiment, the method includes the following steps:

Step S301: The device for recording changes in stored data determines the logical block area where the currently changed logical block is located in the LUN.

Specifically, please refer to FIG. 4. Before using the bitmap set to record the change of the logical block, the method also includes presetting the logical block information and corresponding bitmap information of each logical block area, specifically:

Step S401: Divide the storage data in the LUN into multiple logical blocks.

The device for recording changes in stored data divides the stored data in the LUN into multiple logical blocks. For example, the currently allocated capacity of the LUN is 1GB, and the device divides the LUN into 1024 logical blocks with a capacity of 1KB. Each logical block Different logical block numbers are assigned, for example, logical block 0, logical block 1, logical block 2, and so on.

Step S402: Divide the plurality of logical blocks into a first number of logical block areas, wherein the first number is at least 2.

For example, a LUN includes 1024 logical blocks, and the 1024 logical blocks are divided into 128 logical block areas, and each logical block area includes 8 logical blocks. For example, the first logical block area includes logical blocks 0 to 7, and the second The logical block area includes logical blocks 8 to 15 . . . and so on.

Of course, the device does not necessarily divide the logical blocks in order. In other implementations, according to actual needs, non-contiguous logical blocks in the LUN can be divided into one logical block area, and the number of logical blocks in each logical block area It is not limited to all being the same. At this time, after the device divides the logical block area, the logical block information (such as the logical block number) of each logical block area needs to be saved locally, so that the device can save The logical block information determines the logical block area where the logical block in the LUN is located.

Step S403: Determine the corresponding bitmap information of each logical block.

The device sets a corresponding bitmap information for each logical block area in the LUN, and saves the corresponding bitmap information of each logical block area locally, wherein the corresponding bitmap information of the logical block area includes the The number of digits of the corresponding bitmap of the logical block area is equal to the number of logical blocks of the logical block area, and each bit of the corresponding bitmap of the logical block area is respectively corresponding to whether a logical block used to record the logical block area occurs Change, each bit can be set as the first mark or the second mark, the first mark is used to indicate that the logic block corresponding to the bit has changed, and the second mark is used to indicate that the logic block corresponding to the bit The block has not changed. For example, the first mark is 1, and the second mark is 0. When the logic block changes, it will correspond to the position 1 of the logic block. If the logic block does not change, it will correspond to the position 0 of the logic block. By judging whether the bit is 0 or 1, it can be known whether the logic block corresponding to the bit has changed.

After the device for recording and storing data changes has preset the logical block information and corresponding bitmap information of each logical block area through the above steps S401-S403, the device executes steps S301-S308 when the logical block changes, A bitmap set is used to record the changed logic blocks.

In this embodiment, when the logical block in the LUN changes, the device for recording and storing data changes acquires the currently changed logical block information, and according to the relationship between the preset logical block area and the logical block or the saved logical block The logical block information of the area determines the logical block area where the currently changing logical block in the LUN is located. For example, logical blocks in a LUN are sequentially allocated into multiple logical block areas, and each logical block area includes 8 logical blocks, that is, the first logical block area includes logical blocks 0-7, and the second logical block area includes logical block 8. -16...When the logical block 20 changes, the device obtains the changed logical block number as 20, and according to the relationship between the preset logical block area and the logical block, each logical block area includes 8 logical blocks, That is, it can be calculated that the logical block area where the changed logical block is located is the third logical block area. Alternatively, when the logical block information of each logical block area is saved locally, the device may directly determine the logical block area where the currently changed logical block is located according to the stored information.

Step S302: Query whether the corresponding bitmap of the logical block already exists in the bitmap set.

In this embodiment, when the logical block in the LUN changes, the device for recording the change of the stored data uses the bitmap set to record the change of the logical block in the LUN. The bitmap set can be stored in the storage medium in different data structures (such as tree structure, list). Optimally, the device can also temporarily store the bitmap set in the cache, and regularly store the bitmap set in the cache Data is stored in permanent storage media, such as hard disks and flash. Specifically, the bitmap set is used to place a plurality of bitmaps, wherein each bitmap is used to record a change of a logical block corresponding to one of the logical block areas.

Specifically, when the logical block in the LUN changes, the device for recording and storing data changes obtains the corresponding bitmap information of the logical block area where the currently changed logical block is located according to the preset corresponding bitmap information of each logical block area, And inquire whether the corresponding bitmap of the logical block area of the current changed logical block exists in the bitmap set, if not, execute step S303, and if yes, execute step S304. Wherein, the corresponding bitmap of the logical block area is a bitmap that records changes of logical blocks in the logical block area.

Step S303: Establish the corresponding bitmap of the logical block area in the bitmap set, and find out whether the current changed logical block in the corresponding bitmap is recorded according to the corresponding bitmap information of the logical block area change bits, and set the found bits as the first mark to record the time when the current change logic block changes.

If the corresponding bitmap of the logical block area where the current changed logical block is located is not found in the bitmap set, the device inserts a node in the bitmap tree, and the inserted node carries the logical block where the currently changed logical block is located. The corresponding bitmap of the block area, so as to realize the establishment of the corresponding bitmap of the current changing logical block in the bitmap set. And, the device finds out the information in the corresponding bitmap for recording whether the current changed logical block has changed according to the logical block information corresponding to each bit of the corresponding bitmap in the corresponding bitmap information of the logical block area. bit, and set the found bit as the first mark to record the time when the current change logic block changes.

In addition, in this embodiment, the time when the current change logic block changes is recorded in the memory in the form of a list. Of course, in other embodiments, the time when the current change logic block changes can also be recorded in other ways, which is not limited here .

Step S304: According to the corresponding bitmap information of the logical block area, find out the bit in the corresponding bitmap for recording whether the current changed logical block has changed, and set the found bit as the first flag, Record the time when the current change logic block changes.

If the corresponding bitmap of the logical block area where the current changed logical block is located is found in the bitmap set, the device for recording and storing data changes corresponds to each bit of the corresponding bitmap in the corresponding bitmap information of the logical block area. Logical block information, find out the bit used to record whether the current changing logical block changes in the corresponding bitmap, and set the found bit as the first mark, and record the change in the current changing logical block time.

Step S305: when receiving the copy command, acquire the preset time condition in the copy command.

Furthermore, when the method for recording storage data changes in this application is applied to remote replication technologies (such as asynchronous remote replication, synchronous remote replication, etc.), that is, if the logical block data of the LUN on the host changes, the above steps S301 to S304 are executed to Record the change of the logical block, and copy the changed logical block on the host to the LUN on the slave. When the device for recording changes in stored data receives a copy command for copying the changed logical blocks of the master to the slave, it analyzes the copy command to obtain the preset time conditions included in the command.

Step S306: Searching for bits in the bitmap whose change time of the logic block meets the preset time condition in the bitmap set.

The device for recording the change of stored data traverses the time when the corresponding recorded logical block changes on all bits of all the bitmaps in the recorded bitmap set, and searches out the bitmap where the time when the logical block changes meets the preset time condition bits.

Step S307: Perform a copy operation on the logical block corresponding to the bit in the searched bitmap, and set the bit in the searched bitmap as the second flag after the copying is completed.

The device for recording the change of the stored data finds the logical block in the LUN corresponding to the bit in the searched bitmap according to the bit in the searched out bitmap, and copies the found logical block to the slave, After the copying is completed, set the bit in the searched bitmap as the second flag.

Further, in the embodiment where the method is applied to remote sharing by one master and multiple slaves, the bitmap is also provided with a sharing identifier, and the sharing identifier is used to identify the changes made by the shared slave device to the bitmap record. Whether the logical block has been shared, wherein, when the shared identification is the first shared identification, it means that all shared slave devices have shared the changed logical block recorded in the bitmap, and the shared identification is the second shared When identified, it means that the shared slave device has not completed the sharing of the changed logical block recorded in the bitmap. After the device for recording and storing data changes copies the found logical block to the slave, if it judges that the shared identifier is the first shared identifier, it means that all shared slave devices have changed the bitmap records. If the logical block has been shared, then set the bit in the searched bitmap as the second flag. For example, in the remote replication of one master and five slaves, the logical block of the host LUN changes and is recorded in the corresponding bitmap, and the sharing identifier of the bitmap is set to 5. When each slave completes copying the changed logical block from the host LUN, the sharing identifier is decremented by 1, and when all five slaves complete copying, the sharing identifier is 0. When the device detects that the sharing identifier is 0, set the bit in the searched bitmap as the second flag. In the present application, by setting the sharing identifier in the bitmap, the bitmap carries the sharing status of each shared slave device without configuring a bitmap set for each shared slave device, thereby reducing the occupation of storage resources.

In this embodiment, when copying a changed logical block, based on the time when the logical block changes, a certain period of time or a certain moment of logical block is selected to be copied, which improves the flexibility of copying. And when the time condition is set to before the time to perform the copy, the device can be made not to copy the logical block that changes during the copy process, so as to avoid the synchronous occurrence of the copy and the change of the logical block, which is prone to omission and synchronous occurrence Part of the logic block is copied, or when the copy of a certain logic block is completed, the logic block changes again, and then the update of the corresponding logic block data of the slave cannot be realized.

Step S308: Detect whether there is a bitmap whose bits are all the second marks in the bitmap set, and if so, delete the bitmap from the bitmap set.

Record the timing of the device when the stored data changes or when a detection command is received, detect whether there is a bitmap in the bitmap set that all bits are the second identifier, and if it exists, it means that the logical block corresponding to the bitmap does not currently occur change, so the bitmap whose all bits are the second identifier is deleted from the bitmap set.

Take the first example for illustration, please refer to Figure 5, the application method is applied in asynchronous remote replication, wherein asynchronous remote replication is to copy the storage data that changes in the LUN on the host to the LUN of the slave at regular intervals . At the same time, whenever the logical block data in the LUN on the host changes, the device executes the above steps S301 to S304 to record the change and the time when the current changed logical block occurs. As shown in Figure 5, t0, t1, t2, and t3 represent the time when each bitmap corresponds to a change in the logical block, where t0<t1<t2<t3. When a copy command is received, master-slave data synchronization is started, wherein the preset time condition included in the copy command is: the change time of the logical block to be copied is from t0 to t2. According to the above preset time conditions, the bitmap set can be divided into two areas: synchronization area, including the corresponding bitmap (t0, t1, t2) of the logical block area where the current logical block needs to be synchronized; unsynchronized area, including the current non-synchronization The corresponding bitmap (t3) of the logical block area where the logical block is located. Generally, each time the LUN data changes, the synchronization is performed once, and the time point is updated every time the synchronization is performed, so the synchronization area generally only includes a bitmap of one time point. In this example, the synchronization area includes bitmaps t0, t1, and t2 at multiple time points. During the previous synchronization of bitmaps at time points t0 and t1, the synchronization was not completed due to user interruption or device failure. , so part of the bitmaps at time points t0 and t1 are still left. In this synchronization, the device copies the logical block data in the host LUN corresponding to the bitmaps of t0, t1, and t2 in the synchronization area to the slave LUN to realize the synchronization of the master-slave data, wherein each time a logical block is synchronized , then set the corresponding bit of the corresponding bitmap of the logical block area where the logical block is located as the second mark, and when the device detects that all bits of the bitmap in the bitmap set are the second mark, the bitmap is deleted. And, during the synchronization process, if the logical block of the host LUN changes, the corresponding bitmap will be recorded in the unsynchronized area.

Take the second example for illustration. Please refer to Figure 6. The method of this application is applied in synchronous remote replication. Synchronous remote replication means that when the data stored in the LUN on the host changes, the storage The data is copied to the slave LUN. Similar to the first example, the bitmap set is divided into two areas: the synchronization area (the bitmap corresponding to t4) and the unsynchronized area (the bitmap corresponding to t5), where the bitmap corresponding to t4 is the logic block where the current change logic block is located The bitmap corresponding to the area, and the bitmap corresponding to t5 is the corresponding bitmap of the logical block area where the logical block changed during the synchronization process is located. When the data stored in the LUN on the host changes, the device performs the above steps S301 to S304 to record the change and the time t4 when the current changed logical block occurs, and the device executes the copy command, the copy command The preset time condition of is the current change time t4 or before. Only the bitmap corresponding to t4 in the bitmap set in this example meets this condition, so t4 is put into the synchronization area. According to the copy command, the device copies the logical block data in the master LUN corresponding to the bitmap of t4 in the synchronization area to the slave LUN to realize the synchronization of the master-slave data. Wherein, each time a logical block is synchronized, the The corresponding bit of the corresponding bitmap in the logical block area is set as the second mark, and when the device detects that all the bits of the bitmap in the bitmap set are the second mark, the bitmap is deleted. And, during the synchronization process, if the logical block of the host LUN changes, the corresponding bitmap (that is, the bitmap corresponding to t5) will be recorded in the unsynchronized area.

It should be noted that, in the above examples, the method for recording and storing data changes in this application is applied in remote replication, but this is not a limitation. The method described in this application can also be applied to any other situation that needs to record and store data changes. situation.

In addition, when recording changes in logical blocks in the present application, it is not necessarily limited to recording the time of changes, so as to distinguish logical blocks that change in different time periods. It must be stated that the method of this application can record other information of the logical block as a distinction according to the actual situation, such as recording the storage location of the logical block, etc. Therefore, this application does not make any restrictions on the specific steps of recording the change of the logical block.

Furthermore, in this embodiment, the bitmap set is stored outside the device that records and stores data changes, but in other implementations, the bitmap set can also be stored in the device described in this application, here Not limited. Moreover, the bitmap set described in this application can also be temporarily stored in the cache. Compared with the memory, the cache has a higher reading and writing speed, which further improves the speed of recording whether the stored data changes in the present application. Moreover, when the cache meets certain conditions, such as the cache capacity is greater than the preset capacity, and a power failure occurs, the bitmap set in the cache will be automatically saved in the memory.

In this embodiment, the bitmap set method is used to record whether the logical block in the LUN changes. At the same time, when the logical block changes, the corresponding bitmap of the logical block area where the logical block is located is established, realizing the bitmap on-demand Allocation improves the utilization rate of the bitmap space, reduces the waste of bitmap space, and at the same time reduces the storage resources occupied by the bitmap. Further, when all the bits in the bitmap are the second marks, the bitmap is deleted, so as to release the storage resources occupied by the bitmap and further reduce the storage resources occupied by the bitmap.

Please refer to FIG. 7 . FIG. 7 is a schematic structural diagram of an embodiment of a device for recording and storing data changes in the present application. In this embodiment, the device for recording changes in stored data includes a determination module 710 , a query module 720 , an establishment module 730 and a record module 740 .

The determining module 710 is used for the logical block area where the currently changed logical block in the LUN is located, and sends the determined logical block area to the query module 720 .

In this implementation manner, the LUN adopts thin provisioning (thin) technology, and the LUN can be dynamically expanded. Wherein, as a storage space, the LUN includes at least two logical block areas, and the logical block area includes a plurality of logical blocks, and each logical block is defined as storing data with a certain capacity. In this embodiment, each logical block in the LUN is assigned a different logical block number, and the logical block information of each logical block area is pre-stored locally. For example, the first logical block area includes logical blocks 0 and 1, and the logical block area of the second The second logical block area contains logical blocks 2 and 3...and so on. When the logical block in the LUN changes, the determination module 710 obtains the logical block number of the currently changed logical block in the LUN, and according to the preset relationship between the logical block area and the logical block, each logical block includes two logical blocks, and determines The logical block area where the currently changed logical block is located.

The query module 720 is used to query whether the corresponding bitmap of the logical block already exists in the bitmap set, and send the query result to the establishment module 730 and the record module 740 .

In this embodiment, when the storage data on the logical block in the LUN, that is, the logical block changes, the device for recording the change of the stored data uses the bitmap set to record the change of the logical block in the LUN. The bitmap set can be stored in the storage medium in different data structures (such as tree structure, list). Optimally, the device can also temporarily store the bitmap set in the cache to speed up the processing of the bitmap space, and Regularly store the bitmap set data in the cache in permanent storage media, such as hard disk and flash. Specifically, the bitmap set is used to place a plurality of bitmaps, wherein each bitmap is used to record a change of a logical block corresponding to one of the logical block areas.

Specifically, the device is locally preset with corresponding bitmap information of each logical block in the LUN. When the logical block in the LUN changes, the query module 720 obtains the corresponding bitmap information of the logical block area where the currently changed logical block is located according to the preset corresponding bitmap information, and queries whether the acquired corresponding bitmap information is included in the bitmap set , wherein, the corresponding bitmap of the logical block area is a bitmap that records changes in logical blocks of the logical block area.

For example, a LUN is divided into 16 logical block areas, and each logical block area includes 8 logical blocks. The device for recording and storing data changes presets the corresponding bitmap information of each logical block area as the corresponding bitmap of the first logical block area as the first bitmap, and the corresponding bitmap of the second logical block area as the second bitmap... ...and so on, and each bitmap includes 8 bits, and each bit is used to record whether a logical block has changed. Correspondingly, the first bitmap is used to record the first logical block area, that is, the 1st to 8th logical blocks, and the second bitmap is used to record the second logical block area, that is, the 9th to 16th logical blocks, and the second bitmap is used to record the second logical block area, that is, the 9th to 16th logical blocks. The three-bit map is correspondingly used to record the third logical block area, that is, the 17th to 24th logical blocks...and so on. When the 10th and 15th logical blocks in the LUN change, the determination module 710 determines that the currently changed logical block is located in the second logical block area, and obtains the second logical block area according to the bitmap information corresponding to the preset logical block area. The corresponding bitmap information of the two logical block areas is the second bitmap, and the query module 720 queries whether the bitmap information set up in the current bitmap set includes the second bitmap information, and sends the query result to the building module 730 and the recording module 740.

The establishment module 730 is used to establish the corresponding bitmap of the logical block in the bitmap set when the corresponding bitmap of the logical block is not found, and send the corresponding bitmap to the recording module 740.

When the corresponding bitmap of the logical block area where the current changed logical block is located is not found in the bitmap set, the establishment module 730 establishes a corresponding bitmap of the logical block area where the currently changed logical block is located in the bitmap set, For example, if the set of bitmaps is a tree structure, a node carrying the corresponding bitmap is inserted into the bitmap tree to establish the corresponding bitmap.

The recording module 740 is configured to record the change of the current changed logical block in the corresponding bitmap.

The recording module 740 records the change of the current changed logical block in the corresponding bitmap, for example, setting the bit corresponding to the current changed logical block in the corresponding bitmap as a first mark to identify that the logical block corresponding to the bit has changed , and the bit corresponding to the logical block that has not changed in the corresponding bitmap is set as the second flag to identify that the logical block corresponding to the bit has not changed.

In this embodiment, a bitmap set is used to record whether the logical blocks in the LUN have changed, and the LUN is divided into multiple logical block areas, one logical block area corresponds to a bitmap, and the bitmap generation conditions in the bitmap set are: When the logical block changes, the corresponding bitmap of the logical block area where the logical block is located is established, and there is no need to generate the corresponding bitmap of the logical block area that has not changed, realizing the allocation of bitmaps on demand and reducing the bitmap space At the same time, it also reduces the storage resources occupied by the total bitmap.

It should be noted that the LUN in this embodiment adopts the thin provisioning technology, but in other embodiments, the LUN can also adopt other technologies that can be dynamically expanded, or the LUN cannot be dynamically expanded, and its capacity is fixed. The specific type of LUN does not affect the implementation of the method of this application, and the LUN can be set inside the device that records and stores data changes in this application, or can be set in an external device, and the LUN is not specifically limited here.

Please refer to FIG. 8 . FIG. 8 is a schematic structural diagram of another embodiment of an apparatus for recording and storing data changes in the present application. In this embodiment, the device 810 for recording and storing data changes includes a determination module 811 , a query module 812 , a creation module 813 , a record module 814 , a division module 815 , a copy module 816 and a deletion module 817 .

The division module 815 is configured to divide the storage data in the LUN into a plurality of logical blocks, divide the plurality of logical blocks into a first number of logical block areas, determine the corresponding bitmap information of each logical block area, and Send the corresponding bitmap information of each logical block area to the recording module, wherein the first value is at least 2, and the corresponding bitmap information of the logical block area includes the corresponding bit of the logical block area The number of digits in the map is equal to the number of logical blocks in the logical block area, and each bit of the corresponding bitmap in the logical block area is respectively corresponding to whether a logical block in the logical block area has changed, and each bit can be It is set as a first flag or a second flag, the first flag is used to indicate that the logic block corresponding to the bit has changed, and the second flag is used to indicate that the logic block corresponding to the bit has not changed.

For example, the currently allocated capacity of the LUN is 1GB, and the division module 815 divides the LUN into 1024 logical blocks with a capacity of 1KB, and each logical block is allocated with a different logical block number, for example, logical block 0, logical block 1, logical block 2 etc. The division module 815 divides 1024 logical blocks into 128 logical block areas, each logical block area includes 8 logical blocks, such as the first logical block area includes logical blocks 0 to 7, and the second logical block area includes logical blocks 8 to 15...and so on. The division module 815 sets a corresponding bitmap information for each logical block area in the LUN. For example, the corresponding bitmap of the first logical block area is the first bitmap with a capacity of 8 bits, and each bit in the first bitmap is The sequence correspondence is used to record logical blocks 0-7, and the corresponding bitmap information of other logical block areas is the same as above. Each bit in the bitmap can be set as the first or second flag, the first flag is 1, the second flag is 0, when the logic block changes, the position corresponding to the logic block will be 1, if the logic block If there is no change, it will correspond to the position 0 of the logic block. By judging whether the bit is 0 or 1, it can be known whether the logic block corresponding to the bit has changed.

The determining module 811 is configured to determine the logical block area where the currently changed logical block is located in the LUN. When the logical block in the LUN changes, the determination module 811 obtains the currently changed logical block information, and according to the relationship between the logical block area and the logical block preset by the dividing module 815 or the saved logical block information of each logical block area , to determine the logical block area where the currently changing logical block in the LUN is located.

The query module 812 is used to query whether the corresponding bitmap of the logical block exists in the bitmap set 820 , and send the query result to the establishment module 813 and the recording module 814 .

The bitmap set 820 can be stored in the storage medium in different data structures (such as tree structure, list). Optimally, the device can also temporarily store the bitmap set 820 in the cache, and regularly store the bitmap set 820 in the cache. Atlas data is stored in permanent storage media, such as hard disk and flash. Specifically, the bitmap set 820 is used to place a plurality of bitmaps, wherein each bitmap is used to record a change of a logical block corresponding to one of the logical block areas.

Specifically, when the logical block in the LUN changes, the query module 812 obtains the corresponding bitmap information of the logical block area where the currently changed logical block is located according to the preset corresponding bitmap information of each logical block area, and queries the bitmap Whether the corresponding bitmap of the logical block area of the current changing logical block already exists in the set 820 .

The establishment module 813 is used to establish the corresponding bitmap of the current changed logical block in the bitmap set 820 when the corresponding bitmap of the logical block area is not found, and send the corresponding bitmap to the Record module 814 . For example, the bitmap set 820 has a tree structure, and then a node carrying the corresponding bitmap is inserted into the bitmap tree to establish the corresponding bitmap.

The recording module 814 is used to find out the bit in the corresponding bitmap for recording whether the current changed logical block has changed according to the corresponding bitmap information of the logical block area, and set the found bit as the first mark, recording the time when the current change logic block changes.

In addition, in this embodiment, the time when the current change logic block changes is recorded in the internal or external memory of the device of the present application in the form of a list. Of course, in other embodiments, the time when the current change logic block changes can also be recorded in other ways. Time is not limited here.

The copying module 816 is configured to obtain the preset time condition in the copy command when receiving the copy command, and search out the bit in the bitmap set 820 that the time when the logic block changes meets the preset time condition Bits in the map: performing a copy operation on the logical blocks corresponding to the bits in the searched out bitmap, and setting the bits in the searched out bitmap as the second mark after the copying is completed.

Furthermore, the device for recording and storing data changes in this application can also implement remote replication (such as asynchronous remote replication, synchronous remote replication, etc.), that is, if the logical block data of the LUN on the host changes, the determination module 811 and the query module 812 , the establishment module 813 and the recording module 814 record the change of the logical block, and at the same time, the replication module 816 also copies the changed logical block on the master to the LUN on the slave. When the copy module 816 receives a copy command to copy the changed logical block from the master to the slave, it parses the copy command to obtain the preset time condition included in the command.

The copying module 816 traverses the time when the corresponding recorded logical block changes on all bits of all the bitmaps in the recorded bitmap set 820, and searches out the bits in the bitmap whose logical block changes meet the preset time condition .

The replication module 816 finds out the logical block in the host LUN corresponding to the bit in the searched out bitmap according to the bits in the searched out bitmap, and copies the found logical block to the slave machine. Then, set the bit in the searched bitmap as the second flag.

Further, in the embodiment in which the device of the present application implements one master and multiple slaves for remote sharing, the bitmap is also provided with a sharing identifier, and the sharing identifier is used to identify the logic of the change of the shared slave device to the bitmap record Whether the block has been shared, wherein, when the shared identifier is the first shared identifier, it means that all shared slave devices have shared the changed logical blocks recorded in the bitmap, and the shared identifier is the second shared identifier , it means that the shared slave device has not finished sharing the changed logical blocks recorded in the bitmap. After the copying module 816 copies the found logical block to the slave, if it judges that the shared identifier is the first shared identifier, it means that all the shared slave devices have changed the logical blocks recorded in the bitmap. shared, then setting the bit in the searched bitmap as the second flag.

In this embodiment, when copying a changed logical block, based on the time when the logical block changes, a certain period of time or a certain moment of logical block is selected to be copied, which improves the flexibility of copying. And when the time condition is set to before the time to perform the copy, the device can be made not to copy the logical block that changes during the copy process, so as to avoid the synchronous occurrence of the copy and the change of the logical block, which is prone to omission and synchronous occurrence Part of the logic block is copied, or when the copy of a certain logic block is completed, the logic block changes again, and then the update of the corresponding logic block data of the slave cannot be realized.

The deletion module 817 is configured to detect whether there is a bitmap whose bits are all the second marks in the bitmap set 820 , and if so, delete the bitmap from the bitmap set 820 .

The deletion module 817 detects whether there is a bitmap whose all bits are the second identification in the bitmap set 820 at regular intervals or when receiving the detection command. If it exists, it means that the logical block corresponding to the bitmap is currently unchanged. Therefore, the bitmap whose bits are all the second identifiers is deleted from the bitmap set 820 .

Let us take the first example for illustration. Please refer to FIG. 5 . The device of the present application can realize asynchronous remote replication. The asynchronous remote replication is to copy the changed storage data in the LUN on the host to the LUN of the slave at regular intervals. At the same time, whenever the logical block data in the LUN on the host changes, the device records the change and the time of the current changed logical block through the determination module 811, the query module 812, the establishment module 813 and the recording module 814. As shown in Figure 5, t0, t1, t2, and t3 represent the time when each bitmap corresponds to a change in the logical block, where t0<t1<t2<t3. When receiving the copy command, the copy module 816 starts master-slave data synchronization, wherein the preset time condition included in the copy command is: the change time of the logical block to be copied is from t0 to t2. According to the above preset time conditions, the bitmap set 820 can be divided into two areas: the synchronization area, including the corresponding bitmap (t0, t1, t2) of the logical block area where the logical block that needs to be synchronized currently is located; the unsynchronized area, including the currently unsynchronized Corresponding bitmap (t3) of the logical block area where the logical block to be synchronized is located. Generally, each time the LUN data changes, the synchronization is performed once, and the time point is updated every time the synchronization is performed, so the synchronization area generally only includes a bitmap of one time point. In this example, the synchronization area includes bitmaps t0, t1, and t2 at multiple time points. During the previous synchronization of bitmaps at time points t0 and t1, the synchronization was not completed due to user interruption or device failure. , so part of the bitmaps at time points t0 and t1 are still left. In this synchronization, the replication module 816 copies the logical block data in the host LUN corresponding to the bitmaps of t0, t1, and t2 in the synchronization area to the slave LUN to realize the synchronization of the master-slave data. , the copy module 816 sets the corresponding bit of the corresponding bitmap of the logical block area where the logical block is located as the second flag. When the deletion module 817 detects that all the bits of the bitmap in the bitmap set 820 are the second mark, the bitmap is deleted. At the same time, during the synchronization process, if the logical block of the host LUN changes, the recording module 814 records the corresponding bitmap in the unsynchronized area.

Take the second example for illustration, please refer to Figure 6, the device of this application can realize synchronous remote replication, wherein, synchronous remote replication means that when the data stored in the LUN on the host changes, immediately copy the stored data that has changed in the LUN on the host Copy to the slave LUN. Similar to the first example, the bitmap set 820 is divided into two areas: the synchronization area (the bitmap corresponding to t4) and the unsynchronized area (the bitmap corresponding to t5), where the bitmap corresponding to t4 is the logic block where the current change logic block is located. The corresponding bitmap of the block area, the bitmap corresponding to t5 is the corresponding bitmap of the logical block area where the logical block that changes during the synchronization process is located. When the data stored in the LUN on the host changes, the device records the change and the time t4 of the current changed logic block through the determination module 811, the query module 812, the establishment module 813 and the recording module 814, and the copy module 816 executes the copy command, the preset time condition of the copy command is the current time t4 or before the change, in the bitmap set 820 of this example, only the bitmap corresponding to t4 satisfies this condition, so t4 is put into the synchronization Area. The replication module 816 copies the logical block data in the master LUN corresponding to the bitmap of t4 in the synchronization area to the slave LUN according to the replication command, so as to realize the synchronization of the master-slave data. Wherein, each time a logical block is synchronized, the replication module 816 will The corresponding bit of the corresponding bitmap of the logical block area where the block is located is set as the second flag. When the deletion module 817 detects that all the bits of the bitmap in the bitmap set 820 are the second mark, the bitmap is deleted. Moreover, during the synchronization process, if the logical block of the host LUN changes, the recording module 814 records the corresponding bitmap (that is, the bitmap corresponding to t5) in the unsynchronized area.

It should be noted that when recording changes in logical blocks in this application, it is not necessarily limited to recording the time at which changes occur, so as to distinguish logical blocks that have changed in different time periods. It must be stated that this application can record other information of the logical block as a distinction according to the actual situation, such as recording the storage location of the logical block, etc. Therefore, this application does not make any restrictions on the specific method of recording the change of the logical block.

In addition, in this embodiment, the bitmap set is stored outside the device that records and stores data changes, but in other embodiments, the bitmap set can also be stored in the device described in this application, which is not described here. limited. Moreover, the bitmap set described in this application can also be temporarily stored in the cache. Compared with the memory, the cache has a higher reading and writing speed, which further improves the speed of recording whether the stored data changes in the present application. Moreover, when the cache meets certain conditions, such as the cache capacity is greater than the preset capacity, and a power failure occurs, the bitmap set in the cache will be automatically saved in the memory.

In this embodiment, the bitmap set method is used to record whether the logical block in the LUN changes. At the same time, when the logical block changes, the corresponding bitmap of the logical block area where the logical block is located is established, realizing the bitmap on-demand Allocation improves the utilization rate of the bitmap space, reduces the waste of bitmap space, and at the same time reduces the storage resources occupied by the bitmap. Further, when all the bits in the bitmap are the second marks, the bitmap is deleted, so as to release the storage resources occupied by the bitmap and further reduce the storage resources occupied by the bitmap.

Please refer to FIG. 9 . FIG. 9 is a schematic structural diagram of another embodiment of an apparatus for recording and storing data changes in the present application. In this embodiment, the device for recording and storing data changes includes a processor 910 and a storage medium 920 , wherein the processor 910 and the storage medium 920 are connected through a bus 930 .

The storage medium 920 is used for storing computer instructions executed by the processor 910 and data required to be stored when the processor 910 works.

The processor 910 executes the computer instructions stored in the storage medium 920 to determine the logical block area where the currently changed logical block in the LUN is located, and checks whether the corresponding bitmap of the logical block area already exists in the bitmap set. When the corresponding bitmap of the logical block area is set, the corresponding bitmap of the current changing logical block is established in the bitmap set, and the change of the current changing logical block is recorded in the corresponding bitmap. When the corresponding bitmap of the logical block area is selected, the change of the current changed logical block is directly recorded in the corresponding bitmap.

In this embodiment, the processor 910 divides the storage data in the LUN into multiple logical blocks in advance, divides the multiple logical blocks into a first number of logical block areas, and determines the corresponding bitmap information. Wherein, the first numerical value is at least 2, and the corresponding bitmap information of the logical block area includes that the number of bits of the corresponding bitmap of the logical block area is equal to the number of logical blocks of the logical block area, and the logical block area Each bit of the corresponding bitmap corresponds to recording whether a logical block in the logical block area has changed, and each bit can be set as a first flag or a second flag, and the first flag is used to indicate the The logic block corresponding to the bit has changed, and the second mark is used to indicate that the logic block corresponding to the bit has not changed. For example, the first mark is 1, and the second mark is 0. When the logic block changes, it will correspond to the position 1 of the logic block. If the logic block does not change, it will correspond to the position 0 of the logic block. By judging whether the bit is 0 or 1, it can be known whether the logic block corresponding to the bit has changed.

When a logical block in the LUN changes, the processor 910 determines the logical block area where the currently changed logical block in the LUN is located, and checks whether the logical block already exists in the bitmap set according to the corresponding bitmap information of each logical block area. The corresponding bitmap of the block. The bitmap set is stored in the storage medium. Optimally, the device can temporarily store the bitmap set in the cache to speed up the processing of the bitmap space, and regularly store the bitmap set data in the cache in the permanent storage In the medium, the bitmap set is used to place multiple bitmaps, each of which is a node of the tree, and together constitute the tree structure. Specifically, each of the bitmaps is used to record changes in logical blocks corresponding to one of the logical block areas.

In addition, the manner in which the processor 910 records that the logical block corresponding to the current change has changed is as follows: the processor 910 finds out the corresponding bitmap for recording the current block according to the corresponding bitmap information of the logical block area; Change the bit of whether the logic block changes, and set the found bit as the first mark, and record the time when the current change logic block changes. In this embodiment, the processor 910 records the time when the current changed logic block changes in a list form in the internal or external memory of the device of the present application. Of course, in other embodiments, the change of the current changed logic block can also be recorded in other ways The time is not limited here.

Optimally, the processor 910 is also configured to acquire the preset time condition in the copy command when receiving the copy command; search out the time when the logic block changes in the bitmap set conforms to the preset time condition the bits in the bitmap; performing a copy operation on the logic blocks corresponding to the bits in the searched out bitmap, and setting the bits in the searched out bitmap as the second flag after the copying is completed.

Furthermore, the device for recording storage data changes in this application can also implement remote replication (such as asynchronous remote replication, synchronous remote replication, etc.), that is, if the logical block data of the LUN on the host changes, the processor 910 records the occurrence of the logical block. At the same time, the changed logical block on the master is copied to the LUN on the slave. When the processor 910 receives a copy command to copy the changed logic block of the master to the slave, it parses the copy command to obtain the preset time condition included in the command.

The processor 910 traverses the time when the corresponding recorded logic block changes in all the bits of all the bitmaps in the recorded bitmap set, and searches for bits in the bitmap whose logic block change times meet the preset time condition.

The processor 910 finds out the logical block in the master LUN corresponding to the bit in the searched out bitmap according to the bits in the searched out bitmap, and copies the found logical block to the slave machine. Then, set the bit in the searched bitmap as the second flag. In this embodiment, when copying a changed logical block, based on the time when the logical block changes, a certain period of time or a certain moment of logical block is selected to be copied, which improves the flexibility of copying. And when the time condition is set to before the time to perform the copy, the device can be made not to copy the logical block that changes during the copy process, so as to avoid the synchronous occurrence of the copy and the change of the logical block, which is prone to omission and synchronous occurrence Part of the logic block is copied, or when the copy of a certain logic block is completed, the logic block changes again, and then the update of the corresponding logic block data of the slave cannot be realized.

Further optimally, the processor 910 is further configured to detect whether there is a bitmap whose bits are all the second marks in the bitmap set, and if so, delete the bitmap from the bitmap set.

The processor 910 detects whether there is a bitmap whose all bits are the second identifier in the bitmap set at regular intervals or when receiving the detection command. If it exists, it means that the logic block corresponding to the bitmap is currently unchanged, so the The bitmap whose all bits are the second identifier is deleted from the bitmap set.

It should be noted that when recording changes in logical blocks in this application, it is not necessarily limited to recording the time at which changes occur, so as to distinguish logical blocks that have changed in different time periods. It must be stated that this application can record other information of the logical block as a distinction according to the actual situation, such as recording the storage location of the logical block, etc. Therefore, this application does not make any restrictions on the specific method of recording the change of the logical block.

In addition, in this embodiment, the bitmap set is stored outside the device that records and stores data changes, but in other embodiments, the bitmap set can also be stored in the storage medium of the device described in this application. This is not limited. Moreover, the bitmap set described in this application can also be temporarily stored in the cache. Compared with the memory, the cache has a higher reading and writing speed, which further improves the speed of recording whether the stored data changes in the present application. Moreover, when the cache meets certain conditions, such as the cache capacity is greater than the preset capacity, and a power failure occurs, the bitmap set in the cache will be automatically saved in the memory.

Through the above scheme, this application uses the bitmap set to record the changes of the storage data of the LUN, and only when the logic block changes, the corresponding bitmap of the logic block is established, which is different from the fixed use of a bitmap to record all the storage data of the LUN According to the prior art of changing situations, this application adopts a dynamic bitmap method, so that the total storage space occupied by the bitmap corresponds to the number of logical blocks that change in the LUN, realizing the on-demand allocation of bitmaps and reducing the storage resources occupied. At the same time, It also improves the utilization efficiency of the bitmap and reduces the waste of bitmap memory resources.

In the several implementation manners provided in this application, it should be understood that the disclosed systems, devices and methods may be implemented in other ways. For example, the device implementations described above are only illustrative. For example, the division of the modules or units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components can be Incorporation may either be integrated into another system, or some features may be omitted, or not implemented. In another point, the mutual coupling or direct coupling or communication connection shown or discussed may be through some interfaces, and the indirect coupling or communication connection of devices or units may be in electrical, mechanical or other forms.

The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place, or may be distributed to multiple network units. Part or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, each unit may exist separately physically, or two or more units may be integrated into one unit. The above-mentioned integrated units can be implemented in the form of hardware or in the form of software functional units.

If the integrated unit is realized in the form of a software function unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application is essentially or part of the contribution to the prior art or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium , including several instructions to make a computer device (which may be a personal computer, a server, or a network device, etc.) or a processor (processor) execute all or part of the steps of the methods described in various embodiments of the present application. The aforementioned storage media include: U disk, mobile hard disk, read-only storage medium (ROM, Read-Only Memory), random access storage medium (RAM, Random Access Memory), magnetic disk or optical disk, etc., which can store program codes. medium.

Claims (8)

1. A method for recording and storing data changes, characterized in that the method comprises the following steps: Determine the logical block area where the current changing logical block in the logical unit number LUN is located, wherein the logical unit number LUN includes at least two logical block areas, and the logical block area includes a plurality of logical blocks; Query whether the corresponding bitmap of the logical block area already exists in the bitmap set, wherein the bitmap set is used to place multiple bitmaps, and each bitmap is used to record the logic corresponding to one of the logical block areas block changes, the corresponding bitmap of the logical block area is the bitmap that records the change of the logical block of the logical block area, and the corresponding bitmap of the logical block area changes in the logical block of the logical block area When it is established; each bit of the corresponding bitmap of the logical block area is respectively corresponding to whether a logical block of the logical block area is changed, and each bit can be set as a first mark or a second mark, The first mark is used to indicate that the logic block corresponding to the bit has changed, and the second mark is used to indicate that the logic block corresponding to the bit has not changed; If it does not exist, then establish the corresponding bitmap of the logical block area in the bitmap set, and record the change of the current changed logical block in the corresponding bitmap; If it exists, directly record the change of the current change logic block in the corresponding bitmap; The method also includes: Detecting whether there is a bitmap whose bits are all the second flags in the bitmap set, and if yes, deleting the bitmap from the bitmap set. 2. The method according to claim 1, wherein, before the step of whether the corresponding bitmap of the logical block area already exists in the bitmap set of the query, the method further comprises: Divide the storage data in the logical unit number LUN into a plurality of logical blocks; dividing the plurality of logical blocks into a first number of logical block areas, wherein the first number is at least 2; Determine the corresponding bitmap information of each logical block area, wherein the corresponding bitmap information of the logical block area includes that the number of bits of the corresponding bitmap of the logical block area is equal to the number of logical blocks in the logical block area. 3. The method according to claim 2, wherein the step of recording the change of the current change logic block in the corresponding bitmap comprises: According to the corresponding bitmap information of the logical block area, find out the bit used to record whether the current changed logical block has changed in the corresponding bitmap, and set the found bit as the first mark, and record the The time when the current change logic block changes. 4. method according to claim 3, is characterized in that, described method also comprises: When receiving the copy command, obtain the preset time condition in the copy command; Searching out the bits in the bitmap whose change time of the logic block meets the preset time condition in the bitmap set; performing a copy operation on the logical block corresponding to the bit in the searched out bitmap, and setting the bit in the searched out bitmap as the second mark after the copy is completed; The bitmap is also provided with a sharing flag, and the sharing flag is used to identify whether the changed logical block recorded by the shared slave device has been shared; after the copying is completed, the searched out bit Bits in the map are set for the second flag, including: Whenever a shared slave device completes copying the changed logical block, change the shared identifier in the bitmap corresponding to the copied logical block according to the set rules; When the shared identifier of the bitmap is changed to the first shared identifier, it is determined that all shared slave devices have completed copying, and the bit in the searched bitmap is set as the second flag. 5. A device for recording and storing data changes, characterized in that the device includes a determination module, a query module, a building module and a recording module, The determining module is used to determine the logical block area where the currently changed logical block is located in the logical unit number LUN, and send the determined logical block area to the query module, wherein the logical unit number LUN includes at least two logical blocks an area, the logical block area includes a plurality of logical blocks; The query module is used to query whether the corresponding bitmap of the logical block area already exists in the bitmap set, and sends the query result to the building module and the recording module, wherein the bitmap set is used to place multiple bitmaps, Each of the bitmaps is used to record changes in logical blocks corresponding to one of the logical block areas, and the corresponding bitmap of the logical block area is the bitmap that records changes in logical blocks in the logical block area. The corresponding bitmap of the logical block area is only established when the logical block of the logical block area changes; each bit of the corresponding bitmap of the logical block area corresponds to whether a logical block used for recording the logical block area is change, each bit can be set as a first flag or a second flag, the first flag is used to indicate that the logic block corresponding to the bit has changed, and the second flag is used to indicate that the logic block corresponding to the bit The logic block has not changed; The establishment module is used to establish the corresponding bitmap of the logical block area in the bitmap set when the corresponding bitmap of the logical block area is not queried, and send the corresponding bitmap to the record module; The recording module is used to record the change of the current change logic block in the corresponding bitmap; The device also includes a deletion module, The deletion module is used to detect whether there is a bitmap whose bits are all the second marks in the bitmap set, and if it exists, delete the bitmap from the bitmap set. 6. The device according to claim 5, further comprising a division module, The dividing module is used to divide the storage data in the logical unit number LUN into a plurality of logical blocks, divide the plurality of logical blocks into a first number of logical block areas, and determine the corresponding bit of each logical block area map information, and send the corresponding bitmap information of each logical block area to the recording module, wherein the first value is at least 2, and the corresponding bitmap information of the logical block area includes the logical block The number of bits of the corresponding bitmap of an area is equal to the number of logical blocks of the logical block area. 7. The device according to claim 6, wherein the recording module is specifically configured to, according to the corresponding bitmap information of the logical block area, find out the corresponding bitmap for recording the current change logic Whether the block changes, and set the found bit as the first flag, and record the time when the current change logic block changes. 8. The device according to claim 7, further comprising a replication module, The copy module is used to obtain the preset time condition in the copy command when receiving the copy command, and search out the bitmap in the bitmap set that the time when the logic block changes meets the preset time condition The bits in the searched out bitmap are copied to the logic block corresponding to the bitmap, and after the copying is completed, the bits in the searched out bitmap are set as the second mark; The bitmap is also provided with a sharing identifier, and the sharing identifier is used to identify whether the changed logical block recorded by the shared slave device has been shared; The replication module is also used to: Whenever a shared slave device completes copying the changed logical block, change the shared identifier in the bitmap corresponding to the copied logical block according to the set rules; When the shared identifier of the bitmap is changed to the first shared identifier, it is determined that all shared slave devices have completed copying, and the bit in the searched bitmap is set as the second flag.