A data recovery method and related devices

Abstract

An embodiment of the present application discloses a data recovery method and related devices. After the source device is powered on, it sends the address of the first data to the standby device. The standby device obtains the second data according to the address of the first data, and the standby device sends the second data to the source device. The source device writes the second data into the address of the first data, so that the data on the device is restored from a non-consistent state to a consistent state, significantly reducing the time required for the data to be restored from a non-consistent state to a consistent state.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of Internet technologies, and in particular, to a data recovery method and related devices. Background Art

[0002] Host-layer continuous data protection (CDP) is a data protection method. By installing an input / output (IO) filtering device at the host layer to capture or track data changes, and adopting an asynchronous replication technology to copy file I / O from the source device to the standby device, so as to ensure that the data can be restored to any point in the past. Due to the adoption of the asynchronous replication technology, when the source device shuts down, a part of the data cannot be transmitted in time, and this part of the data that fails to be transmitted is called tail data. When the service switches from the source device to the standby device, due to the tail data not being transmitted to the standby device, there is incomplete data structure on the standby device, and the service cannot run properly on the source device.

[0003] The prior art is to restart the source device in a disaster recovery mode after the source device shuts down. In the disaster recovery mode, the source device no longer generates any new data. The source device in the disaster recovery mode transmits the tail data to the standby device. After the standby device receives the tail data, it obtains complete data structure. When the service switches from the source device to the standby device, the service can run properly. The running data generated by the service on the standby device is then transmitted back to the source device to make the data of the two devices consistent, and the service can switch back to the source device at any time.

[0004] However, in the prior art, the time for the service to switch from the source device to the standby device includes the restart time of the source device and the transmission time of the tail data, and the transmission time of the tail data is relatively long, resulting in a relatively long interruption time of the service and reducing the service efficiency of the service. Summary of the Invention

[0005] The embodiments of the present application provide a data recovery method and related devices, which can significantly reduce the time required for the data to be restored from a non-consistent state to a consistent state.

[0006] The first aspect of the embodiments of the present application provides a data recovery method:

[0007] First, there is a wired or wireless network connection between the standby device and the source device.

[0008] The source device restarts in the disaster recovery mode. In the disaster recovery mode, no new data is written to the hard disk of the source device. After the source device is powered on, it sends the address of the first data to the standby device. The address of the first data is used to indicate the location of the first data in the source device. When the service is switched from the source device to the standby device, service data is generated on the standby device, and this service data is written to the hard disk of the standby device. The standby device obtains the data at the address in its local hard disk that is the same as the address of the first data. This data is called the second data. After the standby device obtains the second data, it sends the second data to the source device, and the source device writes the second data to the address of the first data.

[0009] After the source device is powered on, it sends the address of the first data to the standby device, and the address of the first data is used to indicate the location of the first data in the source device;

[0010] The standby device obtains the second data according to the address of the first data, and the location of the second data in the standby device is the same as the location of the first data in the source device;

[0011] The standby device sends the second data to the source device;

[0012] The source device writes the second data to the address of the first data.

[0013] It can be seen that after the source device sends the address of the first data to the standby device, the standby device obtains the second data in its local service data whose address is the same as the address of the first data and sends it back to the source device, so that the data is restored from a state of non - consistency to a state of consistency. In the prior art, the tail data transmitted to restore application consistency is data generated at multiple time points, while the second data obtained according to the address in the present invention is only the data at the current time point at this address. The data volume of the second data is smaller than the data volume of the tail data in the prior art. Since the data volume to be transmitted becomes smaller and the transmission time becomes shorter, correspondingly, the time required for the data to restore the application consistency state will also become shorter, significantly reducing the time required for the data to be restored from a state of non - consistency to a state of consistency.

[0014] Based on the first aspect, the embodiment of the present application also provides a first implementation manner of the first aspect:

[0015] The data on the source device is remotely copied to the standby device by means of asynchronous replication. When the source device shuts down, a part of the data has not been copied to the standby device. This part of the data that does not meet the application consistency received by the source device before the previous shutdown is called the first data.

[0016] Based on the first implementation of the first aspect, the embodiments of the present application also provide a second implementation of the first aspect:

[0017] The source device periodically stops I / O and writes the data in the cache to the persistent storage physical medium of the hard disk to create a data set with application consistency. After the source device creates a data set with application consistency, during the process of copying the data to the standby device, the source device sends the application consistency information of this data to the standby device, and the application consistency information is used to indicate whether the data is consistent. The source device sends the application consistency information of the first data to the standby device before the previous shutdown. When the source device shuts down, the standby device will receive an instruction to take over the service sent by the disaster recovery system and prepare to take over the service. The standby device takes over the service according to the application consistency information of the first data, and stores the second data generated during the operation of the stored service. The second data is the data that meets the application consistency.

[0018] It can be seen that the standby device can immediately take over the service after the source device shuts down according to the application consistency information of the first data, significantly reducing the service interruption time.

[0019] The embodiments of the second aspect of the present application provide a disaster recovery system, including: a source device and a standby device.

[0020] The source device is used to send the address of the first data to the standby device after booting up, and the address of the first data is used to indicate the location of the first data in the source device;

[0021] The standby device is used to obtain the second data according to the address of the first data, and the location of the second data in the standby device is the same as the location of the first data in the source device;

[0022] The standby device is further used to send the second data to the source device;

[0023] The source device is further used to write the second data into the address of the first data.

[0024] This disaster recovery system is used to execute the method of the foregoing first aspect.

[0025] The embodiments of the third aspect of the present application provide a computer storage medium, which is used to store computer software instructions for the source device or the standby device in the above disaster recovery system, and includes a program designed for the source device or the standby device in the disaster recovery system.

[0026] A fourth aspect of the embodiments of the present application provides a computer program product, which includes computer software instructions that can be loaded by a processor to implement the processes in any one of the data recovery methods in the first aspect above.

[0027] As can be seen from the above technical solutions, the embodiments of the present application have the following advantages: After the source device sends the address of the first data to the standby device, the standby device obtains the second data in the local service data whose address is the same as that of the first data and sends it back to the source device, so that the data is restored from a non-consistent state to a consistent state. In the prior art, the tail data transmitted to restore application consistency is data generated at multiple time points, while in the present invention, the second data obtained according to the address is only the data at the current time point at that address, and the data volume of the second data is smaller than that of the tail data in the prior art. Since the amount of data to be transmitted becomes smaller and the transmission time becomes shorter, correspondingly, the time required to restore the data to the consistent state of the application will also become shorter, significantly reducing the time required for the data to be restored from a non-consistent state to a consistent state. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a disaster recovery system architecture diagram;

[0029] Figure 2 It is a schematic diagram of an embodiment of the data recovery method according to the embodiments of the present application;

[0030] Figure 3 It is a schematic diagram of another embodiment of the data recovery method according to the embodiments of the present application;

[0031] Figure 4 It is a schematic diagram of another embodiment of the data recovery method according to the embodiments of the present application;

[0032] Figure 5 It is a schematic diagram of an embodiment of the disaster recovery system according to the embodiments of the present application;

[0033] Figure 6 It is a schematic structural diagram of the source device according to the embodiments of the present application;

[0034] Figure 7 It is a schematic structural diagram of the standby device according to the embodiments of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0035] The embodiments of the present application provide a data recovery method, which can enable the source device and the standby device to have data consistency, and at the same time, the standby device can take over the service immediately from the data position corresponding to the data position information after the source device shuts down, significantly reducing the service interruption time.

[0036] A disaster recovery system refers to establishing two or more sets of Internet (IT) systems with the same functions in remote locations that can monitor each other's health status and switch functions. When one system stops working due to accidents such as fires or earthquakes, the entire application system can switch to another location so that the system functions can continue to work properly.

[0037] From the perspective of the degree of system protection, disaster recovery systems can be divided into data disaster recovery and application disaster recovery.

[0038] Data disaster recovery means establishing a data system in a remote location, which is a real-time replication of local critical application data; application disaster recovery is based on data disaster recovery and establishes a complete backup application system equivalent to the local production system in a remote location, or they can be mutual backups. In the event of a disaster, the remote system can quickly take over the business operation.

[0039] Continuous Data Protection (CDP) technology is usually adopted in application disaster recovery systems to provide data protection and data recovery. CDP can achieve real-time backup of databases, files, or operating systems locally or remotely, and when a logical error occurs, it can not only ensure continuous external service but also restore and use data at any point in time.

[0040] CDP technology can solve four core problems of application disaster recovery: (1) Real-time backup - ensuring zero data loss; (2) Logical integrity - ensuring the logical integrity of backup data and the usability after data recovery; (3) Rollback to any point in time - retrieving accidentally deleted data and repairing database logical errors without loss; (4) Business continuity - after the production system fails, the backup system can take over the work in a short time to ensure business continuity.

[0041] CDP has three different deployment architectures, namely the host-side deployment architecture, the network-side deployment architecture, and the storage-side deployment architecture. Among them, the host-side architecture installs an agent program on the server that needs CDP protection, and the agent program is responsible for monitoring the hard disk and replicating the changed data. The agent program captures each piece of data written to the hard disk, replicates a copy, adds a timestamp, and then puts it into the buffer, and then sends it through the network to the specified storage location of the CDP server.

[0042] In a disaster recovery system, when using CDP technology for data protection and data recovery, the database consistency principle needs to be satisfied. Database consistency (DC) means that the result of transaction execution must change the database from one consistent state to another. Ensuring database consistency means that when a transaction is completed, all data must have a consistent state. In a relational database, all rules must be applied to the modifications of the transaction to maintain the integrity of all data.

[0043] The embodiments of the present application can be applied to the disaster recovery system architecture as Figure 1 shown. This architecture includes a source device 101 and a standby device 102, where the standby device is also referred to as a disaster recovery end device or a target end device.

[0044] It can be understood that the source device 101 and the standby device 102 in the embodiments of the present application include a processor and a chip.

[0045] The source device 101 is used to run an application program to support the development of the business, record the data generated during the business operation at the same time, and remotely replicate the generated data to the standby device using continuous data and protection CDP technology.

[0046] The source device 101 includes a hard disk 106, and an application program 103, an IO device stack 104, and a CDP program 105 are running in the memory of the source device.

[0047] Among them, the application program 103 is a program running on the source device to support the business. The data generated by the application program 103 is saved in the hard disk and remotely replicated to the standby device using CDP technology. The switch between the source device 101 and the standby device 102 is to ensure the normal operation of the application program so as not to affect the development of the user's business.

[0048] A filtering driver is running in the IO device stack 104 to capture all file access operations in real time. For files that require continuous backup protection by CDP, when the CDP management module intercepts its rewrite operation via the file filtering driver, the changed part of the file data together with the current system time stamp (STS) is automatically backed up to the storage device in advance. Theoretically, any change in file data will be automatically recorded, so it is called continuous data protection.

[0049] The CDP program 105 runs synchronously at both the source device and the standby device. The CDP program can remotely replicate the data of the source device to the standby device, or remotely replicate the data on the standby device to the source device.

[0050] The hard disk 106 is used to store the data generated during the operation of the application. The hard disk of the source device uses remote mirroring technology to generate a mirrored hard disk on the backup device. Under the action of the CDP program 105, the same data can be stored at the same position on the hard disk and the mirrored hard disk.

[0051] The source device has two modes: normal mode and disaster recovery mode. When entering the disaster recovery mode, the application will stop running, and the IO device stack will freeze the IO. Only the CDP program can run. Please refer to Figure 1 Figure (b) in

[0052] The backup device includes a target logical unit number (LUN) 107, and the CDP program 105 runs on the memory of the backup device.

[0053] The CDP program 105 runs synchronously at both ends of the source device and the backup device. The CDP program can remotely copy the data of the source device to the backup device, or remotely copy the data on the backup device to the source device.

[0054] The target LUN 107 is a set of pointers that point to the unchanged data blocks in the snapshot cache and the hard disk subsystem (during the backup process). While the normal business is in progress, a complete backup of the original data is realized by using the LUN. It enables users to extract the current online business data in real time without affecting the normal business (mainly referring to the disaster recovery backup system). Its "backup window" is close to zero, which can greatly increase the continuity of the system business and provide a guarantee for the system to truly operate 7×24.

[0055] To facilitate the understanding of this application, some term definitions involved in this application will be introduced below:

[0056] 1. Continuous data protection (CDP) technology

[0057] The CDP technology is also called continuous backup, which is a storage system that can back up all data whenever any change occurs.

[0058] 2. Disaster recovery system

[0059] The disaster recovery system refers to establishing two or more sets of identical Internet (IT) systems at remote locations, which can monitor the health status and switch functions with each other. When one system stops working due to an accident (such as a fire, earthquake, etc.), the entire application system can be switched to another location so that the system functions can continue to work normally.

[0060] 3. Input / output (IO)

[0061] In a computer, IO refers to the communication between an information processing system (such as a computer) and the external world (which can be a person or other information processing systems). Input refers to the signals or data received by the system, and output refers to the data or signals sent out from the system.

[0062] 4. Application Consistency Information

[0063] The source device periodically stops IO and writes the data in the cache to the persistent storage physical medium of the hard disk to create a data set with application consistency. After the source device creates the data set with application consistency, during the process of copying the data to the backup device, it sends the application consistency information of these data to the backup device, and the application consistency information is used to indicate whether the data is consistent.

[0064] 5. Shutdown

[0065] The system first closes all running programs, and then shuts down the system background services. The system requests a shutdown from the motherboard, and the motherboard disconnects the power supply enable, allowing the power supply to cut off the power supply to most devices, and the computer shuts down completely.

[0066] 6. Takeover of Services

[0067] After the device takes over the services, all the data generated by the service operation will be written into the storage device of the device.

[0068] 7. Disaster Recovery Mode

[0069] In the disaster recovery mode of the device, the CPU switches from the user mode to the kernel mode, and the operating system can access all the hardware of the device. When the CPU is in the user mode, generally, instructions related to IO and memory protection are not allowed to be used.

[0070] 8. First Data

[0071] The data on the source device is remotely copied to the backup device through asynchronous replication. When the source device shuts down, there will be a part of the data that has not been copied to the backup device. The part of the data that does not meet the application consistency received by the source device before the previous shutdown is called the first data, and it is also called the tail data in the disaster recovery system.

[0072] 9. Address of Data

[0073] To access each word in the memory, a corresponding identifier is required. At the hardware level, each word is identified by an address.

[0074] In the embodiments of the present application, the source device sends application consistency information to the standby device. The standby device takes over the service according to the application consistency information sent by the source device to store the second data. The source device sends the address of the first data to the standby device. The standby device obtains the second data according to the address of the first data. The standby device sends the second data to the source device, and the source device writes the second data to the address of the first data.

[0075] Please refer to Figure 2 , and the data recovery method of the embodiments of the present application will be described below:

[0076] 201. The source device sends the application consistency information of the first data to the standby device.

[0077] The CDP program on the source device will periodically write the data in the host's memory to the persistent storage physical medium of the hard disk and freeze the IO, so that the data is complete when it is copied to the standby device. During the process of copying data from the source device to the standby device, the source device will send the application consistency information of the already copied data to the standby device, which is used to indicate whether the copied data is consistent.

[0078] Before the source device shuts down last time, the source device will send the application consistency information created closest to the shutdown to the standby device, and the application consistency information is the same as the application consistency information corresponding to the first data generated after the shutdown.

[0079] 202. The standby device takes over the service according to the application consistency information of the first data to store the second data.

[0080] After receiving the application consistency information of the first data sent by the source device, the standby device takes over the service according to the application consistency information. Starting from when the standby device takes over the service, the second data generated by the service operation is written to the mirror hard disk of the standby device.

[0081] 203. The source device sends the address of the first data to the standby device.

[0082] After the source device generates the first data during the last shutdown, it will restart in the disaster recovery mode. After the source device boots up, it will send the address of the first data to the standby device.

[0083] 204. The standby device obtains the second data according to the address of the first data.

[0084] The data storage device on the standby device is a mirror hard disk corresponding to the hard disk of the source device. Any data written to the source hard disk will be copied to the mirror hard disk of the standby device, and the position where the same data is written to the mirror hard disk of the standby device is the same as the position on the source hard disk.

[0085] After receiving the address of the first data, the standby device obtains the second data at the address in the local mirrored hard disk that is the same as the address of the first data. The position of the second data in the standby device is the same as the position of the first data in the source device.

[0086] 205. The standby device sends the second data to the source device.

[0087] After obtaining the second data according to the address of the first data, the standby device sends the second data to the source device.

[0088] 206. The source device writes the second data to the address of the first data.

[0089] After receiving the second data, the second data will be automatically written to the address of the first data in the source device, overwriting the data at the address of the first data in the source device. After the overwrite is completed, the data in the source device is consistent, and the service can be immediately switched from the standby device to the source device.

[0090] The above describes an embodiment of the data recovery method provided by the embodiments of the present application. Based on the content introduced in the above embodiments, the following will be combined with Figure 3 introduce an application scenario of the data recovery method.

[0091] Figure 3 Figure (a) in Figure 3 Figure (b) in

[0092] 301. The source device sends the application consistency information of the tail data to the standby device.

[0093] Step 301 in this embodiment is similar to step 201 in the embodiment shown in the foregoing Figure 2 and will not be elaborated here.

[0094] 302. The source device records the address of the tail data.

[0095] When the source device shuts down and generates tail data, the source device will record the address of the tail data locally.

[0096] 303. The source device sends the address of the tail data to the standby device.

[0097] Step 303 in this embodiment is similar to step 203 in the embodiment shown in the foregoing Figure 2 and will not be elaborated here.

[0098] 304. The standby device obtains the data at the address of the tail data according to the address of the tail data.

[0099] Step 304 in this embodiment is similar to step 204 in the foregoing Figure 2 illustrated embodiment, and will not be elaborated here.

[0100] 305. The source device writes the data at the address of the tail data on the standby hard disk to the address of the middle tail data on the local hard disk.

[0101] Step 305 in this embodiment is similar to step 206 in the foregoing Figure 2 illustrated embodiment, and will not be elaborated here.

[0102] The above describes an application scenario of the data recovery method provided in the embodiments of the present application. Based on the content introduced in the foregoing embodiments, another application scenario of the data recovery method will be described below in conjunction with Figure 4 introduce another application scenario of the data recovery method.

[0103] The CDP program remotely copies data from the source hard disk to the standby hard disk in an asynchronous replication manner. At the same moment, some data on the source hard disk has not been copied to the standby hard disk, and the data that has not been copied to the standby hard disk will be copied to the standby hard disk later.

[0104] When the source device shuts down, the "01" in the "001101" data has not been copied to the standby hard disk yet. At this time, the "01" is called the first data.

[0105] After the source device shuts down, the standby device immediately starts from the data with application consistency, takes over the service, and new data generated during the service operation is stored on the standby hard disk. Among them, at the address of the first data, the data "00" is generated first, and then the data "01" is generated, overwriting the previously generated data "00".

[0106] The source device restarts in the disaster recovery mode and sends the storage location of the first data in the hard disk, that is, the address of the first data, to the standby device.

[0107] After receiving the address of the first data sent by the source device, the standby device finds the current data "11" at this address. The data at the same position as the address of the first data on the standby hard disk is called the second data. The standby device sends the second data "11" to the source device, and the source device writes the second data "11" to the address of the first data, overwriting the first data "01" with "11". At this time, the data on the source hard disk has consistency.

[0108] The data recovery method in the embodiments of the present application has been described above. Next, the disaster recovery system in the present application will be described in detail. Please refer to Figure 5 , a disaster recovery system, including a source device 501 and a standby device 502:

[0109] The source device 501 is configured to send the address of the first data to the standby device after power-on, and the address of the first data is used to indicate the location of the first data in the source device;

[0110] The standby device 502 is configured to obtain the second data according to the address of the first data, and the location of the second data in the standby device is the same as the location of the first data in the source device;

[0111] The standby device 502 is further configured to send the second data to the source device;

[0112] The source device 501 is further configured to write the second data into the address of the first data.

[0113] Optionally, based on the above Figure 5 corresponding embodiment, in another embodiment provided by the embodiments of the present application,

[0114] The source device 501 is further configured to, when the first data refers to the data that does not meet the application consistency received by the source device before the previous shutdown, send the application consistency information of the first data to the standby device before the previous shutdown;

[0115] The standby device 502 is further configured to take over the service according to the application consistency information to store the second data, and the second data is the data that meets the application consistency.

[0116] Figure 6 FIG. is a schematic structural diagram of a source device provided by the embodiments of the present application. The source device 600 may include one or more central processing units (CPUs) 601 and a memory 605. One or more application programs or data are stored in the memory 605.

[0117] Among them, the memory 605 may be volatile storage or persistent storage. The program stored in the memory 605 may include one or more modules, and each module may include a series of instruction operations on the server. Further, the central processor 601 may be configured to communicate with the memory 605 and execute a series of instruction operations in the memory 605 on the source device 600.

[0118] The source device 600 may further include one or more power supplies 602, one or more wired or wireless network interfaces 603, one or more input / output interfaces 604, and / or one or more operating systems, such as Windows Server TM , Mac OS X TM, Unix TM , Linux TM , FreeBSD TM etc.

[0119] The central processing unit 601 can perform the operations executed by the source device in the foregoing Figures 2 to 4 illustrated embodiments, and the details are not described herein again.

[0120] Figure 7 FIG. is a schematic structural diagram of a standby device provided by an embodiment of the present application. The standby device 700 may include one or more central processing units (CPUs) 701 and a memory 705. One or more application programs or data are stored in the memory 705.

[0121] Among them, the memory 705 may be volatile storage or persistent storage. The programs stored in the memory 705 may include one or more modules, and each module may include a series of instruction operations on the server. Further, the central processing unit 701 may be configured to communicate with the memory 705 and execute a series of instruction operations in the memory 705 on the standby device 700.

[0122] The standby device 700 may further include one or more power supplies 702, one or more wired or wireless network interfaces 703, one or more input / output interfaces 704, and / or one or more operating systems, such as Windows Server TM , Mac OS X TM , Unix TM , Linux TM , FreeBSD TM etc.

[0123] The central processing unit 701 can perform the operations executed by the standby device in the foregoing Figures 2 to 4 illustrated embodiments, and the details are not described herein again.

[0124] Those skilled in the art can clearly understand that for the convenience and brevity of description, the specific working processes of the systems, devices, and units described above may refer to the corresponding processes in the foregoing method embodiments, and are not described herein again.

[0125] In several embodiments provided by the present application, it should be understood that the disclosed systems, devices, and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of the units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the displayed or discussed coupling, direct coupling, or communication connection between each other can be through some interfaces. The indirect coupling or communication connection of the device or unit can be in electrical, mechanical, or other forms.

[0126] The units described as separate components may or may not be physically separated. The components displayed as units may or may not be physical units, that is, they can be located in one place or distributed to multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0127] In addition, in each embodiment of the present application, the functional units can be integrated into one processing unit, or each unit can exist physically alone, or two or more units can 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.

[0128] If the above-mentioned integrated unit is implemented in the form of a software functional 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, in essence, or the part that contributes to the prior art, or all or part of this technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to enable a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in each embodiment of the present application. The foregoing storage medium includes: various media such as USB flash drives, mobile hard disks, read-only memories (ROM, read-only memory), random access memories (RAM, random access memory), magnetic disks, or optical discs that can store program codes.

[0129] Those skilled in the art can clearly understand that for the convenience and brevity of description, the specific working processes of the systems, devices, and units described above can refer to the corresponding processes in the foregoing method embodiments and will not be elaborated herein.

[0130] In several embodiments provided by the present application, it should be understood that the disclosed systems, devices, and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of the units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the displayed or discussed couplings or direct couplings or communication connections to each other can be through some interfaces, and the indirect couplings or communication connections of devices or units can be in electrical, mechanical, or other forms.

[0131] The units described as separate components may or may not be physically separated. The components displayed as units may or may not be physical units, that is, they can be located in one place or distributed to multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0132] In addition, in each embodiment of the present application, the functional units can be integrated in a processing unit, or each unit can exist physically alone, or two or more units can be integrated in one unit. The above-mentioned integrated units can be implemented in the form of hardware or in the form of software functional units.

[0133] If the above-mentioned integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on such an understanding, the technical solution of the present application, in essence, or the part that contributes to the prior art, or all or part of this technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to enable a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in each embodiment of the present application. The foregoing storage medium includes: USB flash drives, mobile hard disks, read-only memories (ROMs), random access memories (RAMs), magnetic disks, or optical discs, and other various media that can store program codes.

Claims

1. A data recovery method, characterized in that, comprising: After the source device is powered on, it sends the address of the first data to the standby device. The address of the first data is used to indicate the location of the first data in the source device. The first data refers to the data that does not meet the application consistency received by the source device before the previous shutdown; The standby device obtains the second data according to the address of the first data. The location of the second data in the standby device is the same as the location of the first data in the source device; The standby device sends the second data to the source device; The source device writes the second data into the address of the first data.

2. The data recovery method according to claim 1, characterized in that, The method further comprises: Before the previous shutdown, the source device sends the application consistency information of the first data to the standby device; The standby device takes over the service according to the application consistency information to store the second data, and the second data is the data that meets the application consistency.

3. A disaster recovery system, characterized in that, comprising a source device and a standby device: The source device is used to send the address of the first data to the standby device after being powered on. The address of the first data is used to indicate the location of the first data in the source device. The first data refers to the data that does not meet the application consistency received by the source device before the previous shutdown; The standby device is used to obtain the second data according to the address of the first data. The location of the second data in the standby device is the same as the location of the first data in the source device; The standby device is further used to send the second data to the source device; The source device is further used to write the second data into the address of the first data.

4. The disaster recovery system according to claim 3, characterized in that, The source device is further used to send the application consistency information of the first data to the standby device before the previous shutdown; The standby device is further used to take over the service according to the application consistency information to store the second data, and the second data is the data that meets the application consistency.

5. A computer-readable storage medium, comprising instructions, when the instructions run on a computer, causing the computer to execute the method according to any one of claims 1 to 2.

6. A computer program product containing instructions, when it runs on a computer, causing the computer to execute the method according to any one of claims 1 to 2.

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