CN100478904C - Method and device for protecting snapshot - Google Patents

Abstract

The invention discloses a snapshot protection method. A snapshot copy is created for the snapshot, and operations are performed on the snapshot and the snapshot copy respectively. The invention also provides a corresponding snapshot protection device. Because the present invention uses the snapshot copy to back up the snapshot data, even if the snapshot data is modified, the data at the snapshot time point can be restored through the snapshot copy, which provides effective protection for the snapshot; at the same time, based on the snapshot and several copies of the snapshot, It can meet the parallel operation requirements for snapshot data at the same point in time.

Description

Snapshot protection method and device

technical field

The invention relates to the technical field of data protection, in particular to a snapshot protection method and device.

Background technique

With the wide application and continuous development of information science and technology, the amount of data is increasing rapidly, and data protection is becoming more and more important. In order to quickly generate a copy of the data object of the business application at a certain point in time without interrupting the host business, and occupy less storage space, a virtual snapshot technology has been proposed to perform a snapshot of the application data at a certain point in the business operation. backup. In this article, volumes that will provide data storage and access space for business applications are called production volumes. After the snapshot is created, the access to the snapshot can be performed simultaneously with the access to the production volume. When the production volume wants to restore the data at the snapshot time point, the snapshot rollback can be performed on the production volume, which ensures the reliability of the data to a certain extent. and integrity.

The general method of existing virtual snapshot technology is described as follows:

1. When creating a snapshot, generate a mapping table indicating where the actual data of the snapshot is stored. Obviously, at the beginning of snapshot creation, the address pointers in its mapping table all point to the production volume. An example of this process is shown in Figure 1. The snapshot indicates the data A, B, C, and D of the production volume at a certain moment through the mapping table. At this time, the snapshot data shares the data storage space of the production volume.

2. When modifying the production volume, first copy the data to be modified to the resource volume of the snapshot, and modify the mapping table of the snapshot so that the pointer points to the corresponding position in the resource volume, and then modify the production volume. This method It is called Copy-On-Write (COW: Copy-On-Write). An example of this process based on Figure 1 is shown in Figure 2. When the host needs to write data "D" in the production volume to "E", first copy "D" to the resource volume of the snapshot, and then copy the production volume Change "D" in "E" to "E", and modify the snapshot mapping table so that the pointer corresponding to data "D" points to the corresponding location in the resource volume. Of course, if the part that has been copied before writing is modified again, it can be directly carried out without copying before writing.

It can be seen from the above that the virtual snapshot establishes a logical copy of the production volume data at the creation time point, and the snapshot data and the production volume data share the physical storage space as much as possible. When reading a snapshot, according to the mapping information in the mapping table of the snapshot, read data from the corresponding location in the production volume or the resource volume of the snapshot; when writing a snapshot, according to the mapping information in the mapping table, if the part to be written Already pointing to the resource volume of the snapshot, then overwrite the data to the corresponding location in the resource volume according to the pointer; if the part to be written still points to the production volume, write the data to the resource volume, and modify the mapping table so that the pointer Points to the corresponding location in the resource volume.

In the process of proposing the present invention, the inventors of the present invention found that the above-mentioned virtual snapshot technology has at least the following defects: the snapshot data cannot be protected, and once the user modifies the snapshot data, the production volume cannot be restored to the data at the original snapshot time point; And it is not conducive to meeting the requirements of some application scenarios, for example, the requirement that multiple application hosts process snapshot data at a certain point in time at the same time.

Contents of the invention

An embodiment of the present invention provides a snapshot protection method capable of providing protection for snapshot data, including: obtaining an instruction for creating a snapshot copy of the first snapshot; creating a copy of the first snapshot according to the instruction for creating a snapshot copy; An operation instruction of a snapshot and/or a copy of the first snapshot; according to the operation instruction, a corresponding operation is performed on the first snapshot and/or the copy of the first snapshot.

The embodiment of the present invention also provides a corresponding snapshot protection device, including: a protection trigger unit, configured to obtain an instruction to create a snapshot copy of the first snapshot; a copy creation unit, configured to create the first snapshot according to the instruction for creating a snapshot copy the copy of the first snapshot; the operation triggering unit is used to obtain the operation instruction of the first snapshot and/or the copy of the first snapshot; the operation execution unit is used for according to the operation instruction, the first snapshot and/or the first snapshot copy Take the appropriate action.

The embodiment of the present invention adopts the method of creating a snapshot copy for the snapshot and performing operations on the snapshot and the snapshot copy respectively; since the snapshot data is backed up by the snapshot copy, even if the snapshot data is modified, the snapshot time point can be restored through the snapshot copy Data provides effective protection for snapshots; at the same time, based on snapshots and several copies of snapshots, it can meet the parallel operation requirements for snapshot data at the same point in time, for example, it can meet the requirements of multiple application hosts to process snapshot data at a point in time at the same time wait.

Description of drawings

Fig. 1 is a schematic diagram of creating an existing virtual snapshot;

FIG. 2 is a schematic diagram of an existing virtual snapshot copy-before-write operation;

3 is a schematic flow chart of a snapshot protection method according to Embodiment 1 of the present invention;

FIG. 4 is a schematic diagram of creating a snapshot copy through data copy in Embodiment 1 of the present invention;

FIG. 5 is a schematic flowchart of a snapshot protection method according to Embodiment 2 of the present invention;

6 is a schematic diagram of creating a snapshot copy by copying a mapping table in Embodiment 2 of the present invention;

7 is a schematic diagram of a snapshot and a copy-before-write snapshot copy in Embodiment 2 of the present invention;

FIG. 8 is a schematic diagram of writing a snapshot in Embodiment 2 of the present invention;

FIG. 9 is a schematic flowchart of a snapshot protection method according to Embodiment 3 of the present invention;

10 is a schematic diagram of creating a snapshot copy by copying a mapping table and a resource volume in Embodiment 3 of the present invention;

FIG. 11 is a schematic flowchart of a snapshot protection method according to Embodiment 4 of the present invention;

12 is a schematic diagram of creating a snapshot copy through a shared mapping table in Embodiment 4 of the present invention;

13 is a schematic diagram of a snapshot and a copy-before-write snapshot copy in Embodiment 4 of the present invention;

FIG. 14 is a schematic diagram of writing a snapshot in Embodiment 4 of the present invention;

Fig. 15 is a schematic diagram of the logical structure of a snapshot protection device according to Embodiment 5 of the present invention;

Fig. 16 is a schematic diagram of the logical structure of a snapshot protection device according to Embodiment 6 of the present invention;

Fig. 17 is a schematic diagram of the logical structure of a snapshot protection device according to Embodiment 7 of the present invention;

FIG. 18 is a schematic diagram of a logical structure of a snapshot protection device according to Embodiment 8 of the present invention.

Detailed ways

The embodiment of the present invention provides a snapshot protection method, which creates a snapshot copy for the snapshot, and performs operations on the snapshot and the snapshot copy respectively. The embodiment of the present invention also provides a corresponding snapshot protection device. Each will be described in detail below.

Embodiment 1. A snapshot protection method, the process of which is shown in FIG. 3 , including:

A1. Obtain an instruction to create a snapshot copy for the first snapshot.

The first snapshot in this embodiment has a general meaning, that is, a data object that stores data in an image manner. The first snapshot can be created directly from the production volume, or it can be a snapshot after the modification operation is performed; and if the created snapshot copy still retains the image-like data structure, that is, it can still be called a "snapshot", then the first A snapshot can also be a copy of another snapshot, which means that a copy of a copy of a snapshot can be instructed to be recreated.

The same snapshot can be instructed to create a snapshot copy one or more times, and the instruction to create a snapshot copy can be made at the beginning of creation of the first snapshot or at any time after creation. The specific method and timing of issuing instructions can be determined according to the application situation, including but not limited to the following examples:

In order to protect the original data of the snapshot, you can instruct the creation of a snapshot copy before the snapshot needs to be modified;

In order to protect the modified snapshot, you can instruct to create a modified snapshot copy after the snapshot is modified, or before the snapshot is restored, or before it is modified again;

In order to provide snapshots to multiple application hosts, you can create snapshot copies not less than the number of hosts at the beginning of snapshot creation, or create snapshot copies at any time according to the instructions to increase the number of snapshots.

A2. Create a copy of the first snapshot according to the instructions for creating a snapshot copy.

A copy of the snapshot can be created in various ways that can completely preserve the snapshot data information, including but not limited to:

Mode 1: Data copying is performed on the data corresponding to the mapping table of the first snapshot, and the content of the data copy is used as a copy of the first snapshot. An example of this method is shown in Figure 4. In Figure 4, the first snapshot saves the data images A, B, C, and D of the production volume at a certain time, and several complete copies of the first snapshot can be copied through data copying, respectively Snapshot copies 1 to n. The number and timing of duplication are determined by the instruction to create a snapshot copy obtained in step A1. The application of the snapshot copy includes but is not limited to the following examples:

To protect the first snapshot, create snapshot copy 1 of the first snapshot. When the first snapshot is modified and the production volume wants to restore the data at the time point of the first snapshot, copy the snapshot copy 1 to the first snapshot first. Then perform a snapshot rollback on the production volume;

For multi-host applications, instruct to create snapshot copies 1~n of the first snapshot, and then map to multiple hosts according to application requirements;

To protect the modified first snapshot, it is instructed to create a snapshot copy of the modified first snapshot every time the first snapshot is modified.

Method 2: Create a copy of the first snapshot using an image data structure, so that the snapshot and the snapshot copy partly share or share the data storage space as much as possible. The snapshot and the snapshot copy can only share the data in the production volume, or they can also share the copy-before-write data, etc. The snapshot copy created in this way has the same data structure as the snapshot, and can also be regarded as a snapshot of the production volume. Operations are handled in the same way as snapshots.

A3. Obtain an operation instruction on the first snapshot and/or a copy of the first snapshot.

The operation instruction referred to in this article includes the operation instruction of keeping the content of the data object unchanged and the operation instruction of modifying the data object, wherein:

The operation of keeping the content of the data object unchanged includes: the read operation of the snapshot or the snapshot copy; in the case that the snapshot or the snapshot copy adopts the image data structure, when the data image is modified, the data content of the snapshot or the snapshot copy is not changed. Copy-before-write operations, etc. Such operation instructions may be made to a specified snapshot or snapshot copy, or to certain snapshots or snapshot copies. For example, you can instruct to read a specified snapshot; you can also instruct all snapshots and snapshot copies that share data in the production volume to perform a copy-before-write operation due to data modification in the production volume. Of course, for the snapshot copy obtained through full copy of data copy, since it uses independent physical storage, it will not be affected when the data of the production volume is modified.

Operations that modify data objects include write operations on snapshots or snapshot copies, recovery operations, etc. These operations usually indicate a specified execution object, such as instructing to write a specified snapshot or snapshot copy.

In addition, in order to better control the operability of the snapshot and the snapshot copy, the operation instruction may also include a special status setting instruction, which is usually made for the specified snapshot or snapshot copy. By instructing to set the status of the specified snapshot or snapshot copy as available or unavailable, better data protection and avoid misoperation. For example, it can be stipulated that when the snapshot status is set to unavailable, no modification operations can be performed on the snapshot to ensure that the data content of the snapshot remains unchanged; an application scenario of this example is to create the snapshot after it is created by the production volume. Several copies of the snapshot are provided for application or testing, and the snapshot is set to be unavailable to ensure the integrity and accuracy of the original data.

A4. Perform corresponding operations on the first snapshot and/or a copy of the first snapshot according to the operation instruction.

The specific operation content can be executed according to the operation instructions, and both the snapshot and the snapshot copy can be used as independent operation objects. It should be noted that based on the creation method of the snapshot copy, it is possible to copy the data content during the process of creating the snapshot copy in step A2. The operation instruction of A3, and the operation instruction involves the snapshot copy being created, the following methods can be adopted:

If the operation instruction is for the content of the copied part of the snapshot copy, follow the instruction; if the operation instruction is for the content of the uncopied part of the snapshot copy, you can wait for the part to be copied before performing the corresponding operation.

This embodiment adopts the method of creating a snapshot copy of the snapshot and performing operations on the snapshot and the snapshot copy respectively; since the snapshot data is backed up by the snapshot copy, even if the snapshot data is modified, the snapshot time point data can be restored through the snapshot copy , provides effective protection for snapshots; at the same time, based on snapshots and several copies of snapshots, it can meet the parallel operation requirements for snapshot data at the same point in time.

Several methods for protecting snapshots by creating snapshot copies are proposed below based on the first embodiment.

Embodiment 2. A snapshot protection method. Compared with the method of creating a snapshot copy by copying data provided in Embodiment 1, the difference is that the snapshot copy is created by copying the mapping table. The process is shown in Figure 5, including :

B1. Acquire an instruction to create a snapshot copy for the first snapshot.

For this step, refer to step A1 in Embodiment 1.

B2. According to the instruction of creating a snapshot copy, copy the mapping table of the first snapshot and create a second snapshot, use the copied mapping table as the mapping table of the second snapshot, and use the second snapshot as a copy of the first snapshot.

An example of this copy creation method is shown in Figure 6. In Figure 6, the first snapshot saves the data images A, B, C, and D of the production volume at a certain time, and the second snapshot is generated by copying the mapping table of the first snapshot as the second snapshot. A copy of a snapshot, similarly, the mapping table of the first snapshot can also be copied again to generate a third snapshot as another copy of the first snapshot (of course, the third snapshot can also be the first snapshot obtained by copying the mapping table of the second snapshot copy of the second snapshot).

The snapshot copy generated by copying the mapping table has the same data structure as the original snapshot, and can also be regarded as a snapshot of the production volume, and can be modified and created like a normal snapshot.

B3. Obtain an operation instruction for the first snapshot and/or the second snapshot. For this step, refer to step A3 in Embodiment 1, and the example is as follows:

B31. Obtain copy-before-write instructions for each snapshot when data modification occurs in the production volume;

B32. Obtain an instruction to modify the specified snapshot.

B4. Perform corresponding operations on the first snapshot and/or the second snapshot according to the operation instruction.

For example, for the operation instruction obtained in step B31, the execution steps are as follows:

B411. Copy the production volume data that needs to be modified to the snapshot shared resource volume;

B412. Modify the address corresponding to the data in the mapping table of the first snapshot and the mapping table of the second snapshot to the address of the data in the snapshot shared resource volume.

Based on Figure 6, the schematic diagram of the above steps B411 and B412 is shown in Figure 7. When the host needs to write the data "D" in the production volume to "E", first copy "D" to the shared resource volume of the snapshot, and then Then modify the "D" in the production volume to "E", and modify the mapping table of each snapshot, so that the pointer corresponding to the data "D" points to the corresponding location in the snapshot shared resource volume. Since the third snapshot in FIG. 7 also shares the data of the production volume, the mapping table of the third snapshot also needs to be modified. Of course, if the host modifies the part of the production volume data that has already been copied before write, it can be modified directly without performing the copy before write operation.

Since the mapping table of the first snapshot needs to be copied when the second snapshot is created, if the copy-before-write instruction is obtained before the copying of the mapping table is completed, it can be determined whether the mapping information targeted by the instruction has been copied, and if it has been copied, Then execute the instruction according to the above process. If it has not been copied, that is, the content related to the instruction in the second snapshot has not been created, it can be considered that the copy-before-write instruction is only made for the first snapshot, so there is no need to update the second snapshot that is being created. Two snapshots carry out this instruction.

For the operation instruction obtained in step B32, the execution steps are as follows:

B421, judging whether the data to be modified has been copied to the private resource volume of the specified snapshot, if yes, then perform step B424; if not, then perform step B422;

B422. Copy the data to be modified to the private resource volume of the specified snapshot;

B423. Modify the address corresponding to the data in the mapping table of the specified snapshot to the address of the data in the private resource volume of the specified snapshot;

B424. Modify data at a corresponding address in the private resource volume of the specified snapshot.

Based on Figure 7, the schematic diagram of the above steps B421 to B424 is shown in Figure 8. When the host needs to modify the data "C" in the first snapshot to "F", first copy "C" to the private resource of the first snapshot volume, and then modify the original address information of "C" in the mapping table of the first snapshot to the new address information in the private resource volume of the first snapshot, and then modify the "C" in the private resource volume of the first snapshot to " F". Of course, if the subsequent host still needs to write the first snapshot, if the data to be modified has been copied to the private resource volume of the snapshot, it can be directly written into the private resource volume. In addition, when performing the above steps, step B422 can also be omitted, directly write the data to be written into the snapshot private resource volume, and then modify the corresponding pointer of the snapshot mapping table to point to the written data.

In this embodiment, the copy of the snapshot is created by duplicating the mapping table. The snapshot and the copy of the snapshot not only share the data of the production volume but also have a shared resource volume, and only the modified part of the specified snapshot is stored in its private resource volume, so that the snapshot and its Replicas share public data as much as possible to save storage space. At the same time, the snapshot copy has the same user attributes as the snapshot, and is still a snapshot of the production volume, which can be operated and processed in the same way as the snapshot.

Embodiment 3. A snapshot protection method. Compared with the method of creating a snapshot copy by copying data provided in Embodiment 1, the difference is that the snapshot copy is created by copying the mapping table and the resource volume. The process is shown in FIG. 9 display, including:

C1. Acquire an instruction to create a snapshot copy for the first snapshot.

For this step, refer to step A1 in Embodiment 1.

C2. Create a second snapshot by copying the mapping table and resource volume of the first snapshot according to the instructions for creating a snapshot copy, and use the second snapshot as a copy of the first snapshot; the specific steps include:

C21. Copy the mapping information in the mapping table of the first snapshot;

C22. Determine whether the address in the copied mapping information points to the resource volume of the first snapshot, if so, execute step C23; if not, continue to execute step C21, and copy another mapping information in the mapping table of the first snapshot;

C23. Copy the data corresponding to the address in the resource volume of the first snapshot to the resource volume of the second snapshot, and make the mapping information of this part in the mapping table of the second snapshot point to the corresponding address in the resource volume of the second snapshot. address, and then proceed to step C21 to copy another mapping information in the mapping table of the first snapshot;

C24. The mapping table of the first snapshot is copied.

An example of this copy creation method is shown in Figure 10. The first snapshot in Figure 10 saves the data images A, B, C, and D of the production volume at a certain time, where data A, B, and C point to the production volume, and data D points to The resource volume for the first snapshot. Generate the mapping table of the second snapshot by copying the mapping table of the first snapshot. For data A, B, and C, only copy its mapping information. When copying the mapping information of data D, since the data points to the resource volume of the first snapshot, Therefore, it is necessary to copy the data D to the resource volume of the second snapshot, and then point the mapping information of the data D in the mapping table of the second snapshot to the corresponding address in the resource volume of the second snapshot. Similarly, the mapping table and resource volume of the first snapshot can also be copied again to generate a third snapshot as another copy of the first snapshot (of course, the third snapshot can also be obtained by copying the mapping table and resource volume of the second snapshot copy of the second snapshot).

Snapshot copies made by duplicating mapping tables and resource volumes are identical to existing snapshots, so they can be manipulated in exactly the same way as existing ones.

C3. Obtain an operation instruction for the first snapshot and/or the second snapshot. For this step, refer to step A3 in Embodiment 1, and the example is as follows:

C31. Obtain a copy-before-write instruction for each snapshot when data modification occurs in the production volume;

C4. Perform corresponding operations on the first snapshot and/or the second snapshot according to the operation instruction.

For example, for the operation instruction obtained in step C31, the execution steps are as follows:

C411. Copy the production volume data that needs to be modified to the resource volume of each snapshot;

C412. Modify the address corresponding to the data in the mapping table of each snapshot to the address of the data in the resource volume of the corresponding snapshot.

Since the snapshot and the copy of the snapshot in this embodiment have the same properties as the existing snapshot, the copy-before-write operation of the existing snapshot can be used to perform the copy-before-write operation. Of course, similar to Embodiment 2, if the mapping table of the second snapshot has not been copied when the copy-before-write is executed, it can be judged whether the mapping information targeted by the indication has been copied, and if it has been copied, execute according to the above process This instruction is enough. If it has not been copied, that is, the content related to the instruction in the second snapshot has not been created, it can be considered that the copy-before-write instruction is only made for the first snapshot, so it is not necessary to execute the instruction for the second snapshot being created. .

If what is obtained in step C3 is a modification instruction for a specified snapshot, for example, a modification instruction for the first snapshot or the second snapshot, it can also be executed in the same way as the existing snapshot writing method, and will not be described again.

In this embodiment, the copy of the snapshot is created by duplicating the mapping table and the resource volume. The nature of the created snapshot copy is exactly the same as that of the existing snapshot. It will increase the complexity of system processing.

Embodiment 4. A snapshot protection method. Compared with the method of creating a snapshot copy by copying data provided in Embodiment 1, the difference is that the snapshot copy is created by using a shared mapping table. The process is shown in FIG. 11 , including :

D1. Obtain an instruction to create a snapshot copy for the first snapshot.

For this step, refer to step A1 in Embodiment 1.

D2. Create a second snapshot according to the instruction of creating a snapshot copy, use the mapping table of the first snapshot as a shared mapping table between the first snapshot and the second snapshot, and use the second snapshot as a copy of the first snapshot.

An example of this copy creation method is shown in Figure 12. In Figure 12, the first snapshot saves the data images A, B, C, and D of the production volume at a certain time. By using the mapping table of the first snapshot as the first snapshot and the second The shared mapping table of the second snapshot creates the second snapshot as a copy of the first snapshot. Similarly, the shared mapping table can also be used as the mapping table of the third snapshot to create another copy of the first snapshot (of course, the third snapshot can also can be considered as a copy of the second snapshot).

The snapshot copy generated through the shared mapping table has the same data structure as the original snapshot, and can also be regarded as a snapshot of the production volume, and can be modified and created like a normal snapshot.

D3. Obtain an operation instruction for the first snapshot and/or the second snapshot. For this step, refer to step A3 in Embodiment 1, and the example is as follows:

D31. Obtain a copy-before-write instruction for each snapshot when data modification occurs in the production volume;

D32. Obtain an instruction to modify the specified snapshot.

D4. Perform corresponding operations on the first snapshot and/or the second snapshot according to the operation instruction.

For example, for the operation instruction obtained in step D31, the execution steps are as follows:

D411. Copy the production volume data that needs to be modified to the snapshot shared resource volume;

D412. Modify the address corresponding to the data in the shared mapping table to the address of the data in the snapshot shared resource volume.

Based on Figure 12, the schematic diagram of the above steps D411 and D412 is shown in Figure 13. When the host needs to write the data "D" in the production volume as "E", first copy "D" to the shared resource volume of the snapshot, and then Then change "D" in the production volume to "E", and modify the shared mapping table of the snapshot so that the pointer corresponding to the data "D" points to the corresponding location in the shared resource volume of the snapshot. Since the snapshot and its replicas use the same shared mapping table, only one modification is required.

For the operation instruction obtained in step D32, the execution steps are as follows:

D421. Determine whether the data to be modified has been copied to the private resource volume of the designated snapshot, if yes, execute step D424; if not, execute step D422;

D422. Copy the data to be modified to the private resource volume of the specified snapshot;

D423. Write the address of the data in the private resource volume of the specified snapshot into the private mapping table of the specified snapshot, and the priority of the private mapping table is higher than that of the shared mapping table;

D424. Modify data at a corresponding address in the private resource volume of the specified snapshot.

Based on Figure 13, the schematic diagram of the above steps D421 to D424 is shown in Figure 14. When the host needs to modify the data "C" in the first snapshot to "F", first copy "C" to the private resource of the first snapshot volume, and then create a private mapping table to save the data address pointing to the private resource volume, and then modify the "C" in the private resource volume to "F". At this time, for the first snapshot, two addresses are stored in the same data, and because the priority of the private mapping table is higher, the first snapshot will consider the address in the private mapping table to be the real address. Of course, if the subsequent host still needs to write the first snapshot, if the data to be modified has been copied to the private resource volume of the snapshot, it can be directly written into the private resource volume. In addition, when performing the above steps, step D422 can also be omitted, directly write the data to be written into the private resource volume of the snapshot, and then save the address of the written data into the private mapping table of the snapshot.

In this embodiment, the copy of the snapshot is created by sharing the mapping table. The snapshot and the copy of the snapshot not only share the common data as much as possible, but also share the information of the mapping table as much as possible, saving storage space to the greatest extent.

It should be understood that the software implementing the snapshot protection method of the present invention can be stored in a computer-readable medium. When the software is executed, it includes the following steps: obtaining an instruction to create a snapshot copy of the first snapshot;

Create a copy of the first snapshot according to the instruction for creating a copy of the snapshot; obtain an operation instruction for the first snapshot and/or a copy of the first snapshot; The replica performs the corresponding operation. The readable medium, such as: ROM/RAM, magnetic disk, optical disk, etc.

The snapshot protection device according to the embodiment of the present invention will be described in detail below.

Embodiment 5. A snapshot protection device 10, as shown in FIG. 15 , includes:

The protection triggering unit 11 is configured to acquire an instruction to create a snapshot copy for the first snapshot.

The copy creating unit 12 is configured to create a copy of the first snapshot according to the instruction for creating a snapshot copy acquired by the protection triggering unit 11 .

An operation triggering unit 13, configured to obtain an operation instruction on the first snapshot and/or a copy of the first snapshot.

The operation execution unit 14 is configured to perform corresponding operations on the first snapshot and/or the copy of the first snapshot created by the copy creation unit 12 according to the operation instruction acquired by the operation trigger unit 13 .

In order to better control the operability of snapshots and snapshot copies, the operation instruction acquired by the operation trigger unit 13 may include an instruction to set the state of the specified snapshot; the corresponding operation execution unit 14 may include a state control unit 141 for When the operation triggering unit 13 acquires the status setting instruction for the specified snapshot, it sets the status of the specified snapshot as available or unavailable.

The snapshot protection device in this embodiment can refer to Embodiment 1 to implement a corresponding snapshot protection method. When the copy creation unit 12 uses the data copy method provided in the first embodiment to create a snapshot copy, the copy creation unit 12 can be acted as a data copy unit, and is used to copy the data corresponding to the mapping table of the first snapshot, so as to The content of the data copy serves as a copy of the first snapshot.

Embodiment 6. A snapshot protection device 20, as shown in FIG. 16 , includes:

The protection triggering unit 21 is configured to obtain an instruction to create a snapshot copy for the first snapshot.

The table copying unit 22 serving as a copy creation unit is used to copy the mapping table of the first snapshot and create a second snapshot according to the instruction of creating a snapshot copy obtained by the protection triggering unit 21, and use the copied mapping table as the copy of the second snapshot. The mapping table uses the second snapshot as a copy of the first snapshot.

An operation triggering unit 23, configured to acquire an operation instruction on the first snapshot and/or a copy of the first snapshot. The acquired operation instructions include copy-before-write instructions for each snapshot when data modification occurs on the production volume, modification instructions for a specified snapshot, status setting instructions for a specified snapshot, and the like.

The operation execution unit 24 is configured to perform corresponding operations on the first snapshot and/or the copy of the first snapshot created by the copy creation unit 22 according to the operation instruction acquired by the operation trigger unit 23, which may specifically include:

A state control unit 241, configured to set the state of the specified snapshot as available or unavailable when the operation trigger unit 23 acquires a state setting indication for the specified snapshot;

The copy-before-write unit 242 is used to copy the production volume data that needs to be modified to the snapshot shared resource volume when the operation trigger unit 23 obtains the copy-before-write indication for each snapshot; the mapping table of the first snapshot and the second snapshot The address corresponding to the data in the mapping table is modified to the address of the data in the snapshot shared resource volume;

The data modification unit 243 is used to determine whether the data to be modified has been copied to the private resource volume of the specified snapshot when the operation trigger unit 23 obtains a modification instruction to the specified snapshot, and if so, directly modify the private resource volume of the specified snapshot If not, copy the data to be modified to the private resource volume of the specified snapshot, and modify the address corresponding to the data in the mapping table of the specified snapshot so that the data is in the private resource volume of the specified snapshot address, modify the data at the corresponding address in the private resource volume of the specified snapshot.

The snapshot protection device in this embodiment can refer to Embodiment 2 to implement a corresponding snapshot protection method.

Embodiment 7. A snapshot protection device 30, as shown in FIG. 17 , includes:

A protection triggering unit 31, configured to acquire an instruction to create a snapshot copy for the first snapshot.

Replica creation unit 32, comprising:

The table replication subunit 321 is configured to create a second snapshot and copy the mapping table of the first snapshot as the mapping table of the second snapshot according to the instruction of creating a snapshot copy obtained by the protection triggering unit 31, and use the second snapshot as the mapping table of the first snapshot. copy;

The volume copying subunit 322 is used to judge whether the mapping information of the copied part points to the resource volume of the first snapshot when the table copying subunit 321 copies the mapping table of the first snapshot, and if so, transfer the resource volume of the first snapshot to The data at the corresponding address is copied to the resource volume of the second snapshot, and the mapping information of this part in the mapping table of the second snapshot points to the corresponding address in the resource volume of the second snapshot.

An operation triggering unit 33, configured to obtain an operation instruction on the first snapshot and/or a copy of the first snapshot. The acquired operation instructions include copy-before-write instructions for each snapshot when data modification occurs on the production volume, status setting instructions for the specified snapshot, etc.;

The operation executing unit 34 is configured to perform corresponding operations on the first snapshot and/or the copy of the first snapshot created by the copy creation unit 32 according to the operation instruction acquired by the operation triggering unit 33, which may specifically include:

A state control unit 341, configured to set the state of the specified snapshot as available or unavailable when the operation trigger unit 33 acquires a state setting indication for the specified snapshot;

The copy-before-write unit 342 is used to copy the production volume data that needs to be modified to the resource volume of each snapshot when the operation trigger unit 33 obtains the copy-before-write instruction for each snapshot; The corresponding address is modified to the address of the data in the resource volume of the corresponding snapshot.

The snapshot protection device in this embodiment can refer to Embodiment 2 to implement a corresponding snapshot protection method.

Embodiment 8. A snapshot protection device 40, as shown in FIG. 18 , includes:

The protection triggering unit 41 is configured to obtain an instruction to create a snapshot copy for the first snapshot.

The table sharing unit 42 serving as a copy creation unit is used to create a second snapshot according to the instruction of creating a snapshot copy obtained by the protection trigger unit 41, and use the mapping table of the first snapshot as the shared mapping table of the first snapshot and the second snapshot, Take the second snapshot as a copy of the first snapshot.

An operation triggering unit 43, configured to obtain an operation instruction on the first snapshot and/or a copy of the first snapshot. The acquired operation instructions include copy-before-write instructions for each snapshot when data modification occurs on the production volume, modification instructions for a specified snapshot, status setting instructions for a specified snapshot, and the like.

The operation execution unit 44 is configured to perform corresponding operations on the first snapshot and/or the copy of the first snapshot created by the copy creation unit 42 according to the operation instruction acquired by the operation trigger unit 43, which may specifically include:

A state control unit 441, configured to set the state of the specified snapshot as available or unavailable when the operation trigger unit 43 acquires a state setting indication for the specified snapshot;

The copy-before-write unit 442 is configured to copy the production volume data that needs to be modified to the snapshot shared resource volume when the operation trigger unit 43 obtains the copy-before-write indication for each snapshot; The address of the data is changed to the address of the data in the snapshot shared resource volume.

The data modification unit 443 is used to determine whether the data to be modified has been copied to the private resource volume of the specified snapshot when the operation trigger unit 43 obtains the modification instruction of the specified snapshot, and if so, directly modify the private resource volume of the specified snapshot If not, copy the data to be modified to the private resource volume of the specified snapshot, write the address of the data in the private resource volume of the specified snapshot into the private mapping table of the specified snapshot, and the private The priority of the mapping table is higher than that of the shared mapping table, and the data at the corresponding address in the private resource volume of the specified snapshot is modified.

The snapshot protection device in this embodiment can refer to Embodiment 4 to implement a corresponding snapshot protection method.

It should be understood that the copy creation unit of the snapshot protection device in the embodiment of the present invention may include the data copy unit, table copy unit, table copy subunit, volume copy subunit, and table sharing unit in the fifth to eighth embodiments, so that The snapshot protection device can provide different copy creation methods at the same time. When a snapshot copy needs to be created, the user can choose the actual method or the system can determine the actual method according to certain rules. Of course, if it is determined that a snapshot copy has been created using one of the above methods, subsequent operations on the snapshot copy should be performed in a corresponding manner.

It can be seen from the above embodiments that the embodiment of the present invention adopts the method of creating a snapshot copy for the snapshot and performing operations on the snapshot and the snapshot copy respectively; since the snapshot data is backed up by the snapshot copy, even if the snapshot data is modified, the The snapshot copy is used to restore the data at the snapshot time point, which provides effective protection for the snapshot; at the same time, based on the snapshot and several copies of the snapshot, it can meet the parallel operation requirements for the snapshot data at the same time point. In addition, the embodiment of the present invention also provides a method for making the snapshot copy and the snapshot share common data or even a shared mapping table, which can effectively save storage resources.

The snapshot protection method and device provided by the embodiments of the present invention are described above in detail. This article uses specific examples to illustrate the principle and implementation of the present invention. The description of the above embodiments is only used to help understand the method of the present invention. and its core idea; at the same time, for those of ordinary skill in the art, according to the idea of the present invention, there will be changes in the specific implementation and scope of application. limits.

Claims (15)

1, a kind of snapshot guard method is characterized in that, comprising:

Obtain indication to the first snapshot creation snapshot copy;

According to the indication of described establishment snapshot copy, duplicate the mapping table of first snapshot and create second snapshot, with the mapping table of the described mapping table that duplicates, with the copy of second snapshot as first snapshot as second snapshot;

Obtain to produce and perm when giving birth to data modification, to the preceding copy indication of writing of each snapshot; The production volume copying data that needs are revised is rolled up to the snapshot shared resource; With in the mapping table of the mapping table of first snapshot and second snapshot with this data corresponding address, be revised as the address of these data in described snapshot shared resource volume;

Obtain specifying the modification indication of snapshot; Whether the data of judge to need revising have copied in the privately owned resource volume of specifying snapshot, if, then directly revise the privately owned resource of specifying snapshot roll up in the data of appropriate address; If not, then

The copying data that needs are revised is rolled up to the privately owned resource of specifying snapshot,

With specifying in the mapping table of snapshot and this data corresponding address, be revised as the address of these data in specifying the privately owned resource volume of snapshot,

Revise the data of appropriate address in the privately owned resource volume of specifying snapshot.

2, snapshot guard method according to claim 1 is characterized in that, described first snapshot is the copy of another snapshot.

3, snapshot guard method according to claim 1 and 2 is characterized in that, also comprises: the state that obtains specifying snapshot is provided with indication; Specify the state of snapshot to be set to available or unavailable.

4, a kind of snapshot guard method is characterized in that, comprising:

Obtain indication to the first snapshot creation snapshot copy;

According to the indication of described establishment snapshot copy, create second snapshot and duplicate the mapping table of the mapping table of first snapshot, with the copy of second snapshot as first snapshot as second snapshot;

When duplicating the mapping table of first snapshot, judge whether the map information of the part of duplicating points to the resource volume of first snapshot, if, then the data with appropriate address in the resource of first snapshot volume copy in the resource volume of second snapshot, and make the map information of this part in the mapping table of second snapshot point to appropriate address in the resource volume of second snapshot;

Obtain to produce and perm when giving birth to data modification, to the preceding copy indication of writing of each snapshot; The production volume copying data that needs are revised is rolled up to the resource of each snapshot; With in the mapping table of each snapshot with this data corresponding address, be revised as the address of these data in the resource of the snapshot of correspondence volume.

5, snapshot guard method according to claim 4 is characterized in that, described first snapshot is the copy of another snapshot.

6, according to claim 4 or 5 described snapshot guard methods, it is characterized in that, also comprise: the state that obtains specifying snapshot is provided with indication; Specify the state of snapshot to be set to available or unavailable.

7, a kind of snapshot guard method is characterized in that, comprising:

Obtain indication to the first snapshot creation snapshot copy;

According to the indication of described establishment snapshot copy, create second snapshot, with the mapping table of first snapshot shared mapping table, with the copy of second snapshot as first snapshot as first snapshot and second snapshot.

Obtain to produce and perm when giving birth to data modification, to the preceding copy indication of writing of each snapshot; The production volume copying data that needs are revised is rolled up to the snapshot shared resource; With in the described shared mapping table with this data corresponding address, be revised as the address of these data in described snapshot shared resource volume.

Obtain specifying the modification indication of snapshot, judge the data that need to revise whether to copy in the privately owned resource volume of specifying snapshot, if, then directly revise the privately owned resource of specifying snapshot roll up in the data of appropriate address; If not, then

The copying data that needs are revised is rolled up to the privately owned resource of specifying snapshot,

The address of these data in specifying the privately owned resource volume of snapshot write in the privately owned mapping table of specifying snapshot, and the priority of described privately owned mapping table is higher than described shared mapping table,

Revise the data of appropriate address in the privately owned resource volume of specifying snapshot.

8, snapshot guard method according to claim 7 is characterized in that, described first snapshot is the copy of another snapshot.

9, according to claim 7 or 8 described snapshot guard methods, it is characterized in that, also comprise: the state that obtains specifying snapshot is provided with indication; Specify the state of snapshot to be set to available or unavailable.

10, a kind of snapshot protective device is characterized in that, comprising:

The protection trigger element is used to obtain the indication to the first snapshot creation snapshot copy;

The copy creating unit is used for the indication according to described establishment snapshot copy, creates the copy of first snapshot;

The operation trigger element is used to obtain the operation indication to the copy of first snapshot and/or first snapshot;

Operation execution unit is used for according to described operation indication the copy of first snapshot and/or first snapshot being carried out corresponding operation;

Described copy creating unit comprises the table copied cells, is used to duplicate the mapping table of first snapshot and creates second snapshot, with the mapping table of the described mapping table that duplicates as second snapshot, with the copy of second snapshot as first snapshot;

Operation that described operation trigger element obtains indication comprises, produce curly hair when giving birth to data modification to copy indication before the writing of each snapshot, to specifying the modification indication of snapshot;

Described operation execution unit comprises writes preceding copy cell, is used for getting access to before the writing of each snapshot during the copy indication at described operation trigger element, and the production volume copying data that needs are revised is rolled up to the snapshot shared resource; With in the mapping table of the mapping table of first snapshot and second snapshot with this data corresponding address, be revised as the address of these data in described snapshot shared resource volume;

Described operation execution unit also comprises the data modification unit, be used for getting access to when specifying the modification indication of snapshot at described operation trigger element, judge whether the data that need to revise have copied in the privately owned resource volume of specifying snapshot, if, the data of appropriate address during then directly the privately owned resource of modification appointment snapshot is rolled up; If not, the copying data that then will need to revise is to the privately owned resource volume of specifying snapshot, with specifying in the mapping table of snapshot and this data corresponding address, be revised as the address of these data in specifying the privately owned resource volume of snapshot, revise the data of appropriate address in the privately owned resource volume of specifying snapshot.

11, snapshot protective device according to claim 10 is characterized in that, the operation indication that described operation trigger element obtains also comprises, the state of specifying snapshot is provided with indication;

Described operation execution unit also comprises status unit, is used for getting access to when the state of specifying snapshot is provided with indication at described operation trigger element, specifies the state of snapshot to be set to available or unavailable.

12, a kind of snapshot protective device is characterized in that, comprising:

The protection trigger element is used to obtain the indication to the first snapshot creation snapshot copy;

The copy creating unit is used for the indication according to described establishment snapshot copy, creates the copy of first snapshot;

The operation trigger element is used to obtain the operation indication to the copy of first snapshot and/or first snapshot;

Operation execution unit is used for according to described operation indication the copy of first snapshot and/or first snapshot being carried out corresponding operation;

Described copy creating unit comprises:

Table replicon unit is used to the mapping table creating second snapshot and duplicate first snapshot mapping table as second snapshot, with the copy of second snapshot as first snapshot,

Volume replicon unit, when being used for duplicating the mapping table of first snapshot in described table replicon unit, judge whether the map information of the part of duplicating points to the resource volume of first snapshot, if, then the data with appropriate address in the resource of first snapshot volume copy in the resource volume of second snapshot, and make the map information of this part in the mapping table of second snapshot point to appropriate address in the resource volume of second snapshot;

The operation indication that described operation trigger element obtains comprises, produces and perms when giving birth to data modification to the preceding copy indication of writing of each snapshot;

Described operation execution unit comprises writes preceding copy cell, is used for getting access to before the writing of each snapshot during the copy indication at described operation trigger element, and the production volume copying data that needs are revised is to the resource volume of each snapshot; With in the mapping table of each snapshot with this data corresponding address, be revised as the address of these data in the resource of the snapshot of correspondence volume.

13, snapshot protective device according to claim 12 is characterized in that, the operation indication that described operation trigger element obtains also comprises, the state of specifying snapshot is provided with indication;

Described operation execution unit also comprises status unit, is used for getting access to when the state of specifying snapshot is provided with indication at described operation trigger element, specifies the state of snapshot to be set to available or unavailable.

14, a kind of snapshot protective device is characterized in that, comprising:

The protection trigger element is used to obtain the indication to the first snapshot creation snapshot copy;

The copy creating unit is used for the indication according to described establishment snapshot copy, creates the copy of first snapshot;

The operation trigger element is used to obtain the operation indication to the copy of first snapshot and/or first snapshot;

Operation execution unit is used for according to described operation indication the copy of first snapshot and/or first snapshot being carried out corresponding operation;

Described copy creating unit comprises the table shared cell, is used to create second snapshot, with the mapping table of the first snapshot shared mapping table as first snapshot and second snapshot, with the copy of second snapshot as first snapshot;

Operation that described operation trigger element obtains indication comprises, produce curly hair when giving birth to data modification to copy indication before the writing of each snapshot, to specifying the modification indication of snapshot;

Described operation execution unit comprises writes preceding copy cell, is used for getting access to before the writing of each snapshot during the copy indication at described operation trigger element, and the production volume copying data that needs are revised is rolled up to the snapshot shared resource; With in the described shared mapping table with this data corresponding address, be revised as the address of these data in described snapshot shared resource volume;

Described operation execution unit comprises the data modification unit, be used for getting access to when specifying the modification indication of snapshot at described operation trigger element, judge whether the data that need to revise have copied in the privately owned resource volume of specifying snapshot, if, the data of appropriate address during then directly the privately owned resource of modification appointment snapshot is rolled up; If not, the copying data that then will need to revise is to the privately owned resource volume of specifying snapshot, the address of these data in specifying the privately owned resource volume of snapshot write in the privately owned mapping table of specifying snapshot, the priority of described privately owned mapping table is higher than described shared mapping table, revises the data of appropriate address in the privately owned resource volume of specifying snapshot.

15, snapshot protective device according to claim 14 is characterized in that, the operation indication that described operation trigger element obtains also comprises, the state of specifying snapshot is provided with indication;

Described operation execution unit also comprises status unit, is used for getting access to when the state of specifying snapshot is provided with indication at described operation trigger element, specifies the state of snapshot to be set to available or unavailable.

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