WO2018120844A1

WO2018120844A1 - Differential data backup method and differential data backup device

Info

Publication number: WO2018120844A1
Application number: PCT/CN2017/096782
Authority: WO
Inventors: 廖基祥; 欧阳戟
Original assignee: 华为技术有限公司
Priority date: 2016-12-29
Filing date: 2017-08-10
Publication date: 2018-07-05
Also published as: CN106776147A; CN106776147B

Abstract

Disclosed are a differential data backup method, a differential data backup device and a storage system. The storage system comprises a processor, a production volume and a target volume. The processor acquires a record of differential data between two numbers, wherein the numbers are used to mark a period in which data is written to the production volume. A first number of the two numbers is a number allocated to data most recently received by the production volume before creating a first snapshot of the production volume; a second number of the two numbers is a number allocated to data most recently received by the production volume after creating a second snapshot of the production volume. The record of differential data comprises logical addresses of the differential data received in the periods marked by all numbers between the two numbers. The processor acquires backup data from the second snapshot according to the record of differential data and sends the backup data to the target volume. The present invention can prevent a data-writing request from being suspended, thus increasing the efficiency of data processing in the storage system.

Description

Differential data backup method and differential data backup device

Technical field

Embodiments of the present invention relate to the field of storage technologies, and in particular, to a differential data backup method and a differential data backup device.

Background technique

A typical data disaster recovery system includes a production center and a disaster recovery center. In the production center, hosts and storage arrays are deployed for normal service operations. In the disaster recovery center, hosts and storage arrays are deployed to take over the services after a disaster occurs in the production center. The storage array of the production center or the disaster recovery center includes multiple data volumes, and the data volume is a logical storage space mapped by physical storage space. After the data generated by the service of the production center is written to the production array, it can be backed up to the disaster recovery center through the DR link and written to the disaster recovery array. To ensure that the data of the disaster recovery center can support the service takeover after the disaster occurs, the data backed up to the disaster recovery array must ensure consistency. Assuring data consistency essentially means that there is a dependency write request, and the dependency needs to be guaranteed. Applications, operating systems, and databases all rely on this logic of writing data request dependencies to run their services. For example, the write data request 1 is completed first, and the write data request 2 is completed. The order is fixed. That is to say, the system will ensure that the write data request 1 is sent after the write data request 1 is completely returned successfully. Therefore, it is possible to rely on an inherent method to recover the service when a failure causes the execution process to be interrupted. Otherwise, such a situation may occur. For example, when reading data, the data stored in the write data request 2 can be read, but the data stored in the write data request 1 cannot be read, which will cause the service to be unrecoverable.

In the prior art, snapshot technology can be used to solve this problem. A snapshot is an image of data at a certain point in time (the point in time when the copy begins). The purpose of the snapshot is to create a state view for the data volume at a specific point in time. Only the data volume can be seen at the time of creation. After this time point, the data volume is modified (new data is written). Will not be reflected in the snapshot view. With this snapshot view, you can make a backup of the data. For the production center, since the snapshot data is “stationary”, the production center can back up the snapshot data to the disaster recovery center after snapshotting the data at each time point, and can complete remote data backup without The effect continues to execute write data requests at the production center. For disaster recovery centers, data consistency requirements can also be met. For example, the data of the data request 2 is successfully backed up to the disaster recovery center, and the data of the data request 1 is not successfully backed up. The data of the disaster recovery center can be restored to the previous state by using the snapshot data before the data request 2.

However, in order to ensure data consistency between the production array and the disaster recovery array, the production array needs to hang the write data request before creating the snapshot to prevent the changed data from being recorded in the snapshot, thus causing data and disaster recovery in the production array. The data in the array is inconsistent. However, hanging write data requests often affects the efficiency of the production array processing data.

Summary of the invention

The present application proposes a differential data backup method and a differential data backup device, which can avoid hanging write data requests and improve data processing efficiency.

The first aspect of the present application provides a differential data backup method, which is applied to a storage system. The storage system includes a processor, a production volume, and a target volume. The processor acquires a record of the difference data between the two numbers. The number is used to identify the time period during which data is written to the production volume. Wherein the first number of the two numbers is a number assigned to the data received by the production volume last time before the first snapshot of the production volume is created. The second of the two numbers is the number assigned to the data received last time for the production volume after the second snapshot of the production volume was created. The record of the difference data includes a logical place of the difference data received within a time period identified by a number between the two numbers site. The processor reads backup data from the second snapshot according to a logical address of the difference data, the backup data being a subset of the difference data. The processor then sends the backup data to the target volume.

According to the differential data backup method provided by the first aspect, the processor acquires a record of the two numbered difference data, and reads the backup data from the second snapshot according to the logical address of the difference data. Since the first number of the two numbers is a number assigned to the data received last time for the production volume before the first snapshot of the production volume is created, and the second number of the two numbers is a creation The number of data that was last received for the production volume after the second snapshot of the production volume, so the difference data is more than the backup data. Then, in the differential backup process provided by the first aspect, there is no need to hang the write data request, and the difference data between the two snapshots can still be backed up to the target volume, thereby ensuring data consistency between the production volume and the target volume. Since there is no need to hang write data requests, the efficiency of data processing can be improved.

In conjunction with the first aspect, in a first implementation of the first aspect, all numbers between the two numbers are changed according to a set condition including a preset backup period arrival or creation of the production A snapshot of the volume. Thereby, the time period in which the data is written to the production volume by the number is realized.

In conjunction with the first aspect or the first implementation of the first aspect, in a second implementation of the first aspect, the second snapshot is a next snapshot of the first snapshot. Since the second snapshot is the next snapshot of the first snapshot, it is guaranteed that the data of each backup is slightly more than the difference data between the adjacent two snapshots, and less than the difference data between the two snapshots that are not adjacent. Reduce the amount of data per backup as much as possible.

In combination with the first aspect or any one of the first aspect, in a third implementation of the first aspect, the method further includes the processor transmitting a logical address of the backup data to the target volume .

In conjunction with the first aspect or any one of the first aspects, in the fourth implementation of the first aspect, the number between the two numbers does not include the second number. Since the second number is the starting number of the next backup, the second number may not be included in the current backup to reduce the amount of data backed up.

The second aspect of the present application provides a differential data backup apparatus for performing a differential data backup method provided by the first method.

The various embodiments of the second aspect of the application are similar to the embodiments of the first aspect.

A third aspect of the present application provides a storage system, including a processor, a production volume, and a target volume, where the processor is configured to perform the differential data backup method provided by the first aspect.

A fourth aspect of the present application provides a storage system including a processor, a memory, a production volume, and a target volume, the processor invoking a program in the memory to execute a differential data backup method provided by the first aspect.

The present application also provides a computer program product comprising a computer readable storage medium storing program code, the program code comprising instructions executable by the storage system of the third aspect or the fourth aspect, and for performing the above At least one method on the one hand.

The above computer program product provided by the application of the present invention can not hang the write data request during the backup process, thereby improving the efficiency of data processing.

DRAWINGS

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings to be used in the embodiments will be briefly described below.

FIG. 1 is a schematic diagram of an application scenario according to an embodiment of the present invention;

2 is another application scenario diagram provided by an embodiment of the present invention;

3 is a structural diagram of a storage device according to an embodiment of the present invention;

4 is a schematic flowchart of a differential data backup method according to an embodiment of the present invention;

FIG. 5 is a schematic diagram of changes in numbers during execution of a differential data backup method according to an embodiment of the present invention; FIG.

FIG. 6 is a structural diagram of a differential data backup apparatus according to an embodiment of the present invention.

detailed description

The embodiment of the invention provides a data backup method and a storage system, which can avoid hanging write data requests, thereby improving the efficiency of data processing.

The application scenario of the embodiment of the present invention is introduced below.

As shown in FIG. 1, FIG. 1 depicts a composition diagram of a storage system 10 according to an embodiment of the present invention. The storage system 10 shown in FIG. 1 includes one or more hosts 40 and a storage device 20. The host can be a computing device, such as a terminal device such as a server or a desktop computer. The storage device 20 may be a storage device based on data block data, such as a Storage Area Networking (SAN) device, or a storage device including a file system, such as a Network Attached Storage (NAS) device. This embodiment does not limit the type of the storage device. Between the host 40 and the storage device 20, and between the storage devices 20, the network file system (NFS)/Common Internet File System (CIFS) protocol or Fibre Channel (Fiber Channel, FC) can be used. The protocol communicates.

The storage device 20 includes at least one controller 21 and a plurality of hard disks 22. Controller 21 can include any computing device such as a server, desktop computer, or the like. Inside the controller, an operating system and other applications are installed. The controller 21 can send an input/output (I/O) request to the hard disk 22. For example, a write data request is sent to the hard disk 22 such that the hard disk 22 writes the data to be written carried in the write data request into its storage medium.

The hard disk 22 can be a plurality of types of hard disks, such as Solid State Drive (SSD) or Serial Attached SCSI (SAS) or Fibre Channel (FC) hard disk drives (Hard Disk Drive, HDD). ), where SCSI (Small Computer System Interface) is the abbreviation of the minicomputer system interface or Serial Advanced Technology Attachment (SATA) or Near Line (NL) Serial Attached SCSI (Serial Attached SCSI) , SAS) HDD, not limited here. A Logic Unit (LU) is a logical storage space distributed over one or more hard disks 22, such as production volume 23 and target volume 24 shown in FIG. The host 40 can send a write data request to the storage system 10, the write data request carrying data to be written to the storage system 10, the data can be block data or a file. The controller 21 receives the data and then writes it into the logical unit of the storage device 20. In practical applications, in order to ensure data reliability, data needs to be backed up. For example, the data in the production volume 23 is backed up to the target volume 24. When the data in the production volume 23 is damaged, the data stored in the target volume 24 can be used for recovery.

The embodiment of the present invention is also applicable to another application scenario, as shown in FIG. 2 . 2 depicts a composition diagram of another storage system 10 that includes one or more hosts 40, a storage device 20, and a storage device 30. The storage device 30 is similar to the storage device 20 and includes at least one controller 31 and a plurality of hard disks 32. The structure and function of the controller 31 are similar to those of the controller 21 of FIG. 1. The structure and function of the hard disk 32 are similar to those of the hard disk 22 of FIG. 1, and will not be described herein. The difference from the application scenario described in FIG. 1 is that the backup in FIG. 1 refers to a backup in one storage device, and the backup in FIG. 2 refers to a backup between two storage devices. For example, storage device 20 needs to back up data on its production volume to target volume 33 of storage device 30.

Regardless of the application scenario shown in FIG. 1 or the application scenario shown in FIG. 2, the controller 21 may use data when backing up data in one LU (referred to as a production volume) to another LU (referred to as a target volume). The method of full backup can also adopt the method of incremental backup.

A full backup is a full backup of all the data on the production volume. Incremental backups are backups since the last full backup or Data modified since the incremental backup (whichever is later). Because it is limited to backing up modified data (also known as differential data), this backup is very fast and saves storage space.

The composition of the controller 21 will be described below. As shown in FIG. 3, FIG. 3 depicts a composition diagram of the controller 21 provided by the embodiment of the present invention.

The controller 21 includes at least an interface 211, a processor 212, and a memory 213.

The interface 211 is configured to communicate with the host 40 or the hard disk 22 or the storage device 30.

The processor 212 may be a central processing unit CPU, or an Application Specific Integrated Circuit (ASIC), or one or more integrated circuits configured to implement embodiments of the present invention. The processor 212 can be used to process input/output (I/O) requests to the hard disk 22, back up data in the production volume to the target volume, and the like. Thereby, the controller 21 can implement functions such as IO operation, data backup, and the like. In the embodiment of the present invention, the processor 212 is configured to execute the program 214, and specifically, the related steps in the following method embodiments may be performed.

The memory 213 is configured to store the program 214. The memory 213 may include a cache memory, may also include a high speed RAM memory, and may also include a non-volatile memory, such as at least one hard disk memory. It can be understood that the memory 213 can be a random access memory (RAM), a magnetic disk, a hard disk, or a solid state disk (SSD). The memory 213 can also be used to cache data received from the host 40 or data read from the hard disk 22.

Program 214 can include an operating system, a file system, and other software modules.

The following describes the process of data backup in combination with the above two application scenarios and FIG. Referring to FIG. 4, FIG. 4 is a flowchart of a data backup method provided by this embodiment, and the steps shown in FIG. 4 are performed by the processor 212 shown in FIG. In addition, please refer to FIG. 5, which reflects the change of the number in the following backup process.

In step S101, the storage device 20 receives one or more write data requests. Each write data request includes data to be written (referred to as data) and a logical address of the data to be written. The logical address includes an identifier of a volume, a logical block address (English: logic block address), and a length (English: length). The volume of the volume is used to indicate the volume to be written by the data. In this embodiment, the volume to be written by the data is the production volume as an example. The logical block address indicates the location of the data at the volume, the length representing the size of the data.

In step S102, the storage device 20 allocates a number for each write data request, and the number is used to identify a time period for receiving the write data request. The storage device 20 includes a number table in which a plurality of numbers are included, and each number is sequentially incremented in ascending order. For example, the plurality of numbers are 0, 1, 2, 3, 4, ..., respectively. Write data requests received during a certain period of time are all assigned the same number. Assume that the initial value of the number is the first number 0. When the specific condition is satisfied, the storage device 20 sets the first number to the second number 1, and the second number 1 is the next number of the first number 0. Then the write data request received in the next time period is assigned the second number 1. Alternatively, the storage device 20 maintains a number generator in which the initial value of the number is recorded, assuming that the initial value of the number is the first number 0. The write data request received during a certain period of time is assigned the first number 0. When the specific condition is satisfied, the number initial value in the number generator is subjected to an operation of incrementing by 1, so that the next number of the first number 0 is the second number 1. Then, the write data request received in the next time period is assigned the second number 1. Specific conditions here include the arrival of a preset backup cycle or the creation of a snapshot of the production volume. Illustratively, it is assumed that each write data request is assigned the first number 0 in step S102. The storage device 20 records the correspondence between the first number 0 and the logical address included in each write data request.

As shown in Table 1, during the time period identified by the number 0, the storage device 20 receives three write data requests. The data to be written carried by the first write data request is written to the volume A, the logical block address is 00001, the length of the data is 8 bytes, and the second write data request carries the data to be written. Will be written to volume A, its logical block address is 00002, the length of the data is 8byte; the data to be written carried by the second write data request will be written to volume A, and its logical block address is 00003. The length of the data is 8 bytes.

Step S103, when the preset backup period arrives, the storage device 20 performs a data backup operation.

The data in the production volume is sent to the target volume through a number of backup cycles, which are preset for a length of time. If it is the first backup cycle, then storage device 20 needs to send all of the data in the production volume to the target volume, a process also referred to as full backup. If it is not the first backup cycle, storage device 20 may send all of the data in the production volume to the target volume, or may only send the difference data to the target volume.

Since the storage device 20 is in the process of transmitting data to the target volume, the storage device 20 also continues to receive the write data request. Therefore, the data in the production volume and the data in the target volume are inconsistent. In order to ensure data consistency between the production volume and the target volume, the storage device 20 uses the number to distinguish the write data request before the backup cycle arrives from the write data request after the backup cycle arrives. Also, the storage device 20 does not directly read data from the production volume and sends it to the target volume, but creates a snapshot of the production volume from which data is read and sent to the target volume.

Specifically, when the preset backup period arrives, the storage device 20 performs the following operations:

1. Change the first number to the second number. As mentioned before, the number assigned to each write data request is the first number 0 before the preset backup period arrives. After the preset backup period arrives, the write data request received before the next modification of the number will be assigned the second number 1.

2. Create a first snapshot of the production volume. In a practical application, the storage device 20 periodically creates a snapshot of the production volume.

3. Change the second number to the third number. According to the foregoing description, after the first snapshot of the production volume is created, the storage device 20 will modify the number again. For example, after creating the first snapshot of the production volume, the second number 1 is modified to a third number 2. Then, for the write data request received before the next modification number (when the next backup period arrives) after the second number is changed to the third number, the third number 2 is assigned. However, after the first snapshot of the production volume is created, the write data request received by the storage device 20 is still assigned the second number 1 during the period before the second number is modified to the third number, and the writes are still performed. The data carried by the data request is not recorded in the first snapshot. Therefore, the first snapshot includes data stored in a logical address corresponding to the first number 0 and data stored in a logical address corresponding to the second second number 1.

After the execution of the above operation is completed, the storage device 20 reads the first snapshot of the production volume, and sends the data included in the first snapshot and the logical address of the data to the target volume. As can be seen from the foregoing description, in this backup operation, the backed up data includes data stored in a logical address corresponding to the first number 0 and data stored in a logical address corresponding to a portion of the second number 1.

Through the above steps S101 to S103, the storage device 20 completes a full backup. The process of incremental backup is described below.

It can be seen from the above step S103 that after the second number is changed to the third number, all the write data requests received by the storage device 20 are assigned the third number 2. These write data requests may contain write data requests that modify the data in the production volume. As shown in table 2:

Numbering

Volume identification

Logical block

Length (single

		址site	位：byte)Bit: byte)
22	AA	0000100001	88
22	AA	0000200002	88
22	AA	0000400004	88

As shown in Table 2, during the time period identified by number 2, storage device 20 receives three write data requests. The data to be written carried by the first write data request is written to volume A, the logical block address is 00001, and the length of the data is 8 bytes. Since the logical block address and length of the data carried by the write data request are the same as the logical block address and length of the data carried by the first write data request shown in Table 1, the write data request carries The data is used to cover the data carried by the first write data request shown in Table 1. The data to be written carried by the second write data request will be written to volume A with a logical block address of 00002 and a length of 8 bytes. Since the logical block address and length of the data carried by the write data request are the same as the logical block address and length of the data carried by the second write data request shown in Table 1, the write data request carries The data is used to cover the data carried by the second write data request shown in Table 1. The data to be written carried by the third write data request is newly written data, which will be written to volume A, whose logical block address is 00004, and the length of the data is 8 bytes.

After step S103, the following steps are further included.

Step S104: When the backup period arrives, the storage device 20 modifies the third number to the fourth number. As described earlier, the number assigned to each write data request in step S103 is the third number 2. Then, when the current backup period arrives, the storage device 20 modifies the third number 2 to the fourth number 3, and the fourth number 3 is the number after the third number 2. Then, the write data request received later will be assigned the fourth number 3.

Step S105: Create a snapshot of the production volume. In order to distinguish from the first snapshot in step S103, the snapshot here is referred to as a second snapshot. The point in time for each snapshot is the data consistency point for the production and target volumes. The data consistency point is the point in time at which the data of the production volume is consistent with the data of the target volume.

Step S106: Modify the fourth number to the fifth number. According to the foregoing description, after the snapshot of the production volume is created, the storage device 20 will modify the number again. For example, the fourth number 3 is modified to the fifth number 4. Then, after the fourth number 3 is changed to the fifth number 4, the write data request received before the next modification number (when the next backup period arrives) is assigned the fifth number 4. However, after the second snapshot of the production volume is created, the write data request received by the storage device 20 is still assigned the fourth number 3 during the period before the fourth number 3 is modified to the fifth number 4. The data carried by these write data requests is not recorded in the second snapshot. Therefore, the second snapshot includes data stored in a logical address corresponding to the first number 0, data stored in a logical address corresponding to the second number 1, data stored in a logical address corresponding to the third number 2, and a portion fourth. The data stored in the logical address corresponding to number 3.

Step S107: Determine the logical address of the difference data after the second number up to and before the fifth number. The difference data includes the difference data received in the time period identified by the second number 1, the difference data received in the time period identified by the third number 2, and the difference data received in the time period identified by the fourth number 3, but The difference data received during the time period identified by the fifth number 4 is not included. It can be understood that the second number is the number assigned last time for the write data request before the first snapshot is created, and the fifth number is the number assigned last time for the write data request after the second snapshot is created. Therefore, the difference data after the second number until before the fifth number is more than the data after the first snapshot is created until the second snapshot is created. Exemplarily, the record of the difference data after the second number up to and before the fifth number is as shown in Table 3.

Step S108: Read backup data from the second snapshot according to the logical address of the difference data. The backup data read from the second snapshot may be the difference data or a subset of the difference data. Since only the data stored in the logical address corresponding to the fourth fourth number 3 is recorded in the second snapshot, the storage device 20 may not be able to obtain all the difference data recorded in step S107. For example, assume that within the time period identified by number 3, storage device 20 receives two write data requests. The first write data request is received before the second snapshot is created, and the logical block address of the data carried is 00008 and the length is 4 bytes. The second write data request is received after the second snapshot is created, and the data carried by the logical block address is 00004 and the length is 8 bytes. Then, the storage device 20 can only obtain the data carried by the first write data request from the storage device 20, and the data stored in the second snapshot by the logical address of the second write data request. For example, as shown in Table 3, the second write data request carries 45600000, the logical block address is 00004, and the length is 8 bytes. The data of the logical block address and length in the second snapshot is 12300000. Therefore, storage device 20 still backs up 123000000 to the target volume.

Step S109: Send the backup data to the target volume. In addition, the storage device 20 may further send the logical address of the backup data to the target volume, such that the location where the backup data is saved in the target volume and the location where the backup data is saved in the production volume Consistent.

After the foregoing operations are completed, the storage device 20 completes an incremental backup. Since the storage device 20 records more difference data than the backup data, the storage device 20 does not need to hang the write data request when performing the incremental backup, and can still guarantee Backing up the difference data between the two snapshots to the target volume ensures data consistency between the production volume and the target volume.

This embodiment also provides a difference data backup device 66. The device 66 is located in a storage system that includes a production volume and a target volume. As shown in FIG. 6, the device 66 includes a reading module 661 and a transmitting module 662.

The reading module 661 is configured to obtain a record of difference data between two numbers, and the number is used to identify a time period in which data is written into the production volume, wherein the first number of the two numbers is to create the The number assigned to the data received by the production volume most recently before the first snapshot of the production volume, the second number of the two numbers being the last time the second volume of the production volume was created to receive the production volume a data allocation number, the record of the difference data including a logical address of the difference data received within the time period identified by the number between the two numbers, all numbers between the two numbers not including the a second number; and reading backup data from the second snapshot based on the logical address of the difference data, the backup data being a subset of the difference data. Specifically, the function of the reading module 661 can be referred to the description of step S101 to step S108, and details are not described herein again. In actual implementation, the reading module 661 may be the processor 212 shown in FIG. 3 calling the program 214 in the memory 213. In this case, the processor 212 is a CPU. Alternatively, the reading module 661 can also be implemented independently by the processor 212. In this case, the processor 212 is a Field-Programmable Gate Array (FPGA) or other processing chip.

The sending module 662 is configured to send the backup data to the target volume. The sending module 662 may be the processor 212 shown in FIG. 3 calling the program 214 in the memory 213. In this case, the processor 212 is a CPU. Alternatively, the transmitting module 662 can also be implemented by the processor 212 independently. In this case, the processor 212 is a Field-Programmable Gate Array (FPGA) or other processing chip.

Optionally, all the numbers between the two numbers are changed according to a setting condition, that the preset backup period arrives or a snapshot of the production volume is created.

Optionally, the second snapshot is the next snapshot of the first snapshot.

Optionally, the sending module 662 is further configured to send the logical address of the backup data to the target volume.

Optionally, the number between the two numbers does not include the second number.

In the differential data backup apparatus provided in this embodiment, since the first number of the two numbers is the number assigned to the data received by the production volume last time before the first snapshot of the production volume is created, The second number in the two numbers is the number assigned to the data received last time for the production volume after the second snapshot of the production volume is created, so the difference data is more than the backup data. Therefore, the differential data backup device provided in this embodiment does not need to suspend the write data request, and can still ensure that the difference data between the two snapshots is backed up to the target volume, thereby ensuring data consistency between the production volume and the target volume. Since there is no need to hang write data requests, the efficiency of data processing can be improved.

Those of ordinary skill in the art will appreciate that various aspects of the present invention, or possible implementations of various aspects, may be embodied as a system, method, or computer program product. Thus, aspects of the invention, or possible implementations of various aspects, may be in the form of an entirely hardware embodiment, an entirely software embodiment (including firmware, resident software, etc.), or a combination of software and hardware aspects, They are collectively referred to herein as "circuits," "modules," or "systems." Furthermore, aspects of the invention, or possible implementations of various aspects, may take the form of a computer program product, which is a computer readable program code stored in a computer readable medium.

Computer readable media include, but are not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, devices, or devices, or any suitable combination of the foregoing, such as random access memory (RAM), read only memory (ROM), erasable Programmable read only memory (EPROM), optical disc.

The processor in the computer reads the computer readable program code stored in the computer readable medium such that the processor can perform the functional actions specified in each step or combination of steps in the flowchart.

The computer readable program code can execute entirely on the user's computer, partly on the user's computer, as a separate software package, partly on the user's computer and partly on the remote computer, or entirely on the remote computer or server. . It should also be noted that in some alternative implementations, the functions noted in the various steps in the flowcharts or in the blocks in the block diagrams may not occur in the order noted. For example, two steps, or two blocks, shown in succession may be executed substantially concurrently or the blocks may be executed in the reverse order.

Those of ordinary skill in the art will appreciate that the elements and algorithm steps of the various examples described in connection with the embodiments disclosed herein can be implemented in electronic hardware or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the solution. Different methods may be used to implement the described functionality for each particular application, but such implementation should not be considered to be beyond the scope of the present invention.

The above is only the specific embodiment of the present invention, but the scope of the present invention is not limited thereto, and those skilled in the art can easily think of changes or substitutions within the technical scope of the present invention, and should be covered in Within the scope of protection of the present invention. Therefore, the scope of the invention should be determined by the scope of the claims.

Claims

A differential data backup method, the method being applied to a storage system, the storage system comprising a processor, a production volume, and a target volume, the method being executed by the processor, comprising:

Obtaining a record of difference data between two numbers, the number being used to identify a time period during which data is written to the production volume, wherein the first number of the two numbers is the most recent before the first snapshot of the production volume is created a number assigned to the data received by the production volume at a time, the second number of the two numbers being a number assigned to the data received last time for the production volume after the second snapshot of the production volume is created, The record of the difference data includes a logical address of the difference data received within a time period identified by a number between the two numbers;

Reading backup data from the second snapshot according to a logical address of the difference data, the backup data being a subset of the difference data;

The backup data is sent to the target volume.
The method of claim 1 wherein all of the numbers between the two numbers are changed according to set conditions, the set conditions including a preset backup period arriving or creating a snapshot of the production volume.
The method of any of claims 1-2, wherein the second snapshot is a next snapshot of the first snapshot.
The method of any of claims 1-3, further comprising transmitting a logical address of the backup data to the target volume.
A method according to any one of claims 1-4, wherein the number between the two numbers does not include the second number.
A differential data backup device, wherein the device is located in a storage system, the storage system includes a production volume and a target volume, and the device includes:

a reading module for obtaining a record of difference data between two numbers, the number being used to identify a time period during which data is written into the production volume, wherein the first number of the two numbers is to create the production volume The number assigned to the data received by the production volume last time before the first snapshot, the second number of the two numbers being the data received last time for the production volume after the second snapshot of the production volume was created a number assigned, the record of the difference data comprising a logical address of difference data received within a time period identified by a number between the two numbers, and all numbers between the two numbers do not include the second Numbering; and reading backup data from the second snapshot based on the logical address of the difference data, the backup data being a subset of the difference data;

And a sending module, configured to send the backup data to the target volume.
The apparatus according to claim 6, wherein all of the numbers between the two numbers are changed according to a set condition including a preset backup period arrival or creation of a snapshot of the production volume.
The apparatus according to claim 6 or 7, wherein the second snapshot is a next snapshot of the first snapshot.
Device according to any of claims 6-8, characterized in that

The sending module is further configured to send a logical address of the backup data to the target volume.
Apparatus according to any of claims 6-8, wherein the number between the two numbers does not include the second number.