CN111506453A

CN111506453A - Disk snapshot creating method, device, system and storage medium

Info

Publication number: CN111506453A
Application number: CN201910100438.XA
Authority: CN
Inventors: 廖武钧
Original assignee: Alibaba Group Holding Ltd
Current assignee: Alibaba Cloud Computing Ltd
Priority date: 2019-01-31
Filing date: 2019-01-31
Publication date: 2020-08-07
Anticipated expiration: 2039-01-31
Also published as: CN111506453B

Abstract

The invention discloses a disk snapshot creating method, a device, a system and a storage medium. The method comprises the following steps: sending a snapshot creating command, wherein the snapshot creating command is used for indicating the time points of creating snapshots of the plurality of disks; aiming at a snapshot creating command, receiving a plurality of blocking time points for blocking disk read-write requests in the process of creating snapshots by a plurality of disks; and when the maximum value of the time difference among the blocking time points is smaller than a set first time difference threshold value, determining that the snapshots created by the multiple disks meet the requirement of synchronization precision, and obtaining the multiple snapshots created by the multiple disks synchronously. According to the method provided by the embodiment of the invention, the disk snapshot creation process can be optimized.

Description

Disk snapshot creating method, device, system and storage medium

Technical Field

The present invention relates to the field of computer technologies, and in particular, to a method, an apparatus, a system, and a storage medium for creating a disk snapshot.

Background

Typically, disk snapshots can be used for data backup and disaster recovery. In real business, it will often be necessary to have a certain number of disks to be able to create snapshots at the same point in time. For example, for a disk group consisting of multiple disks, there is data association between the disks, and if a snapshot of a group of disks cannot be created at the same time point, the data recovered from the snapshot of the group of disks may not necessarily satisfy the requirement of disk association, and the snapshot of the group is considered to be unavailable in business.

In view of the above situation, one solution may be to synchronize read and write requests of multiple disks, so that data of the multiple disks are kept in a synchronized state, and snapshots created by the multiple disks based on the disk data synchronized state are regarded as being created at the same time, thereby satisfying requirements for creating snapshots synchronously. However, the synchronization of the read-write requests of multiple disks requires additional machine resources and maintenance cost, and the disk snapshot creation process is complex, which may result in the performance degradation of the disks.

Disclosure of Invention

The embodiment of the invention provides a disk snapshot creating method, a device, a system and a storage medium, which can optimize the disk snapshot creating process.

In a first aspect, an embodiment of the present invention provides a disk snapshot creating method, including:

sending a snapshot creating command, wherein the snapshot creating command is used for indicating the time points of creating snapshots of the plurality of disks; aiming at a snapshot creating command, receiving a plurality of blocking time points for blocking disk read-write requests in the process of creating snapshots by a plurality of disks; and when the maximum value of the time difference among the blocking time points is smaller than a set first time difference threshold value, determining that the snapshots created by the multiple disks meet the requirement of synchronization precision, and obtaining the multiple snapshots created by the multiple disks synchronously.

In a second aspect, an embodiment of the present invention provides a disk snapshot creating apparatus, including:

the snapshot creating module is used for creating snapshots of the plurality of disks according to the snapshot creating command; the device comprises a blocking time receiving module, a snapshot creating module and a snapshot creating module, wherein the blocking time receiving module is used for receiving a plurality of blocking time points for blocking read-write requests of a disk in the process of creating snapshots of the disks aiming at a snapshot creating command; and the synchronization precision determining module is used for determining that the snapshots created by the multiple disks meet the synchronization precision requirement when the maximum time difference value among the multiple blocking time points is smaller than a set first time difference threshold value, so as to obtain the multiple snapshots created by the multiple disks synchronously.

In a third aspect, an embodiment of the present invention provides a disk snapshot creating system, including: a memory and a processor; the memory is used for storing programs; the processor is configured to read executable program code stored in the memory to execute the disk snapshot creating method of the first aspect.

In a fourth aspect, an embodiment of the present invention provides a computer-readable storage medium, where instructions are stored, and when the instructions are executed on a computer, the instructions cause the computer to execute the disk snapshot creating method according to the first aspect.

In a fifth aspect, an embodiment of the present invention provides a disk snapshot creating method, including:

receiving a snapshot creating command, wherein the snapshot creating command is used for indicating a time point for creating a snapshot; when the time point of creating the snapshot is waited, creating disk snapshot data, and transmitting the snapshot data to a snapshot storage system; recording a blocking time point when a disk read-write request is blocked in the process of creating disk snapshot data aiming at a snapshot creating command; and sending the blocking time points to enable the management and control node to determine whether the created snapshot data meets the synchronization precision requirement based on the received multiple blocking time points.

In a sixth aspect, an embodiment of the present invention provides a disk snapshot creating apparatus, including:

a creation command receiving module for receiving a snapshot creation command, the snapshot creation command being used to indicate a time point at which a snapshot is created; the snapshot data creating module is used for creating disk snapshot data and transmitting the snapshot data to the snapshot storage system when waiting for the time point of creating the snapshot; the blocking time recording module is used for recording a blocking time point when the disk read-write request is blocked in the process of creating disk snapshot data aiming at the snapshot creating command; and the blocking time sending module is used for sending the blocking time points so that the management and control node determines whether the created snapshot data meets the requirement of synchronization precision based on the multiple blocking time points.

In a seventh aspect, an embodiment of the present invention provides a disk snapshot creating system, including: a memory and a processor; the memory is used for storing programs; the processor is configured to read executable program code stored in the memory to execute the disk snapshot creating method of the fifth aspect.

In an eighth aspect, an embodiment of the present invention provides a computer-readable storage medium, where instructions are stored in the computer-readable storage medium, and when the instructions are executed on a computer, the instructions cause the computer to execute the disk snapshot creating method in the fifth aspect.

According to the disk snapshot creating method, device, system and storage medium in the embodiment of the invention, whether the creating time of multiple snapshots meets the requirement of synchronous precision on business can be analyzed and judged through the recorded IO blocking time in the disk snapshot creating process, the disk snapshot creating process can be optimized, additional consumed machine resources and maintenance cost are reduced, and the disk performance is improved to a certain extent.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required to be used in the embodiments of the present invention will be briefly described below, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

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

FIG. 2 is a schematic diagram illustrating a disk snapshot creation process according to an embodiment of the present invention;

FIG. 3 is a flow diagram that illustrates a method for multi-disk synchronous snapshot creation, according to one embodiment;

FIG. 4 is a schematic structural diagram illustrating a system for creating snapshots synchronously across multiple disks according to an embodiment of the invention;

FIG. 5 is a flowchart illustrating a disk snapshot creation method of an exemplary embodiment of the present invention;

FIG. 6 is a flow diagram illustrating a disk snapshot creation method according to one embodiment of the present invention;

FIG. 7 is a flow chart illustrating a disk snapshot creation method according to another embodiment of the present invention;

fig. 8 is a schematic structural diagram showing a disk snapshot creation apparatus according to an embodiment of the present invention;

fig. 9 is a schematic structural diagram showing a disk snapshot creation apparatus according to an embodiment of the present invention;

fig. 10 is a block diagram illustrating an exemplary hardware architecture of a computing device in which the disk snapshot creation method and apparatus according to embodiments of the present invention may be implemented.

Detailed Description

Features and exemplary embodiments of various aspects of the present invention will be described in detail below, and in order to make objects, technical solutions and advantages of the present invention more apparent, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not to be construed as limiting the invention. It will be apparent to one skilled in the art that the present invention may be practiced without some of these specific details. The following description of the embodiments is merely intended to provide a better understanding of the present invention by illustrating examples of the present invention.

It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.

For a better understanding of the present invention, a method, an apparatus, a system, and a storage medium for creating a disk snapshot according to embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be noted that these examples are not intended to limit the scope of the present disclosure.

Fig. 1 is a schematic diagram illustrating a distributed system architecture according to an embodiment of the present invention. In the embodiment of the invention, the disk snapshot creating method can be applied to a distributed computing system. The distributed computing system may provide distributed computing services, distributed storage services, and network connectivity services to users.

In the embodiment of the present invention, the distributed system architecture may use a computing device with computing capability, which may be a virtual machine on a machine device with computing capability, as a computing resource through a virtualization technology; and may utilize the storage device as a storage resource. The storage device may be a disk array, a hard disk, a virtual hard disk, or the like.

As shown in fig. 1, the computing devices providing computing resources in the distributed system architecture may be cloud servers. The cloud server can be realized based on cloud computing technology, and can provide computing nodes of distributed computing services. The cloud server is operated and managed in a remote login mode, and the use mode of the cloud server is basically the same as that of a common remote physical server. The storage device may be a cloud disk. The cloud disk can be a disk instance established on a distributed storage system, and the cloud disk is used for reading and writing in a cloud server. The cloud server and the cloud disk can be connected through network equipment.

The Snapshot (Snapshot) is a complete record of the storage content in the disk storage device obtained by backing up the disk data of the disk storage device at a certain time or a certain time point. In one embodiment, incremental backups may be performed on data in disk storage devices.

In some embodiments, disk snapshots are used primarily for backup and disaster recovery. The user can create a plurality of snapshots for a cloud disk at different time points to obtain a snapshot chain formed by the snapshots. If the disk data needs to be restored, the snapshot data can be used for rolling back the disk data, and the data on the disk can be restored to the data content of the snapshot at any time point on the snapshot chain.

In one embodiment, the disk snapshot data may be created at regular time, that is, a time interval between two adjacent times of creating the disk snapshot data may be set, and the time interval is used as a time period for creating the snapshot at regular time. It should be understood that the time period may be, for example, one day, two days, or one week, and in an actual application scenario, the user may determine according to actual needs, which is not specifically limited herein.

In one embodiment, part of the data in the disk data may not change in the process of creating the disk snapshot twice in the neighborhood. That is, there is typically only a small amount of difference in data content between snapshots in a snapshot chain. To save space, the snapshot system may deduplicate the created disk snapshot.

Fig. 2 is a schematic diagram illustrating a disk snapshot creating process for performing incremental backup on disk data according to an embodiment of the present invention. As shown in fig. 2, when creating a disk snapshot, the disk may be divided into a plurality of address intervals according to address offsets, and the disk data in each address interval may be stored as a data slice (which may also be referred to as a data block) of the snapshot in a deduplication manner.

In an embodiment, the size of the address interval may be, for example, 2MB, and in actual application, the user may determine according to actual requirements, which is not specifically limited herein.

As shown in fig. 2, assuming that the disk can be divided into 4 slices (e.g., slice 1, slice 2, slice 3, and slice 4) according to the address offset, a disk snapshot is created at a first point in time, resulting in snapshot a.

As one example, snapshot a may include, for example: section 1-A, section 2-A, section 3-A and section 4-A.

With continued reference to FIG. 2, a disk snapshot is created at a second point in time, resulting in snapshot B. It is assumed that only the data of the disk extents corresponding to slice 1 and slice 3 have been modified during the time intervals between the first time point and the second time point.

Therefore, the slice of snapshot B includes slice 1-B for slice 1 and slice 3-B for slice 3, which are newly created. While slice 2 and slice 4 continue to use slice 2-a and slice 4-a in snapshot a.

As can be seen from fig. 2, when creating a snapshot, each address interval of the current disk is checked: if the slice corresponding to the data content in the address interval is changed compared with the slice corresponding to the data content in the address interval when the snapshot is created at the previous time, the snapshot creates a new slice by using the updated data in the address interval; otherwise, if the snapshot is not changed, the new snapshot will continue to use the slice corresponding to the data content in the address interval when the snapshot was created last time. That is to say, an incremental backup mechanism may be used for creating the disk snapshots, and only data slices in the address interval where data changes between two times of creating the disk snapshots are backed up, so as to improve backup efficiency and save storage space.

In the embodiment of the present invention, the process of creating the snapshot may specifically include the following two steps:

first, metadata of disk data is constructed.

In the step, an address interval with data change relative to the existing snapshot data is determined by analyzing the address interval of the disk, the address interval with data change is marked as an address interval needing to be backed up, and the address interval needing to be backed up is recorded in the snapshot metadata.

Generally, the time spent on building the metadata may be in the order of seconds, for example, 1 to 5 seconds, and in order to avoid that address intervals which need to be backed up in the process of building the metadata of the disk are written with data, the disk blocks read and write requests for the disk until the metadata is completely built.

Secondly, the snapshot data is transmitted to a snapshot storage system.

In this step, when the metadata of the disk data is constructed, the snapshot data of the disk can be determined, and at this time, the snapshot data needs to be transmitted to the snapshot storage system for backup.

In the metadata construction process, the data slices of the address intervals which need to be backed up in the snapshot storage system can be determined, and the data slices of the address intervals are transmitted to the snapshot storage system one by one and stored as the data blocks of the new snapshot.

Through the steps, the snapshot of the disk can be created, the data in the disk can be subjected to incremental backup, the data safety and the data storage efficiency are improved, and the storage space is saved.

In practical application scenarios, there are scenarios that require several disks to be able to create snapshots at the same point in time. As an example, when a disk group is composed of multiple disks, there is data association between the disks, and a snapshot of the disk group cannot be created at the same time point, the data recovered from the snapshot of the disk group may not necessarily satisfy the requirement of data association between the disks, and the snapshot of the disk group is not available in business.

As an example, in business, if a database spans two disks, i.e. the database needs to use two disks, if two disks cannot accurately create snapshots at the same time point, it is possible that disk a recovers data at one time point, e.g. 12 points, 20 minutes and 10 seconds, and disk B recovers data at another time point, e.g. 12 points, 20 minutes and 25 seconds, and a perfect and consistent database cannot be obtained by recovering data.

Therefore, the higher the time precision of synchronously creating the snapshot, the greater the success rate of restoring the complete data using the created snapshot.

In one embodiment, when a maximum value of time differences between a plurality of creation time points corresponding to a plurality of snapshots is within a preset time difference threshold range, the plurality of snapshots can be considered to have availability. As an example, the preset time difference threshold range may be 0.5 seconds or less. It should be understood that the preset time difference threshold range may be set according to the requirement of time precision for creating a snapshot synchronously, and the embodiment of the present invention is not limited in particular.

Fig. 3 is a flowchart illustrating a method for creating a snapshot in synchronization with multiple disks in an embodiment. As shown in fig. 3, in an embodiment, an existing synchronization creating disk snapshot system may include a management and control module, an input/output IO synchronization transit module (which may also be referred to as a synchronization module in the following description of the embodiment for short), and a plurality of disks. When the synchronous snapshot creation system of the disks is used to perform synchronous snapshot creation of multiple disks, the method may include:

step S310, as shown in S1 in fig. 3, determines the operating states of the multiple disks, for example, determines that the operating states of the multiple disks are normal states, for example, a disk state a, which is a running state in which the disks initiate read and write requests to the storage system.

Step S320, as shown in S2 in fig. 3, when the management and control module triggers synchronous creation of the disk snapshot, the IO synchronous transfer module synchronizes read and write requests of the multiple disks to the storage system. At this time, the working states of the plurality of disks are disk state B, i.e. read-write synchronous state.

As shown in fig. 3, in the read-write synchronization state, the IO synchronization relay module receives multiple read-write requests initiated by multiple disks to the storage system, queues the multiple read-write requests, and sequentially issues the multiple read-write requests after queuing.

In step S330, as shown in S3 in fig. 3, the IO synchronous transfer module stops issuing the read/write requests of the multiple disks to the storage system. At this time, the working states of the plurality of disks are disk state C data synchronization state.

As shown in fig. 3, the IO synchronization relay module stops issuing read and write requests of the multiple disks to the storage system at a certain time, so that the multiple disks stop data updating at the certain time, and the multiple disks reach a data synchronization state.

In step S340, as shown in S4 in fig. 3, in the data synchronization state, snapshot metadata is created for each disk, and multiple snapshot metadata are obtained.

In step S350, as shown in S5 in fig. 3, the operating states of the multiple disks are switched to the normal state, and the read/write requests of the multiple disks to the storage system are recovered. And after the snapshot metadata is established, recovering the normal read-write state of the plurality of disks to the storage system.

Through the steps, in the prior art, the IO synchronization transfer module can be used to synchronize the read-write requests of a plurality of disks in advance. That is, the write paths of a plurality of disks may pass through a common access port; when the disk data is created synchronously, the read-write requests of the multiple disks are cut off at the common access, that is, the data write of the multiple disks can be cut off simultaneously, and at the moment, the multiple disks are in a frozen state at the same moment, so that snapshots created by the multiple disks can be regarded as being created at the same moment, and the requirement of creating the snapshots synchronously is met.

Because the synchronization module needs to occupy certain machine and network bandwidth resources, and the synchronization transfer module is used as a service module, the labor maintenance cost is high. Therefore, in the prior art, the snapshot is created for realizing synchronization, and high resources and cost are required to be paid for.

In addition, in the process of creating a snapshot synchronously, when the plurality of disks are switched to be the synchronous module, since the transmission performance of the N disks depends on the performance of the synchronous module, the synchronous module generally issues the synchronous requests of the plurality of disks in serial to ensure the sequential writing of the requests, and when the number of disks is large, the disk capacity is greatly influenced. As an example, say 5 disks, each with a throughput of 100MB/s, but the sync module itself may only have a transfer capacity of 150MB/s, resulting in an average capacity per disk that temporarily drops to 30 MB/s.

And before creating the snapshot, the synchronization module blocks all read-write requests, and restores the read-write requests after all the disks complete the creation of the snapshot metadata. That is, the disk with fast metadata creation needs to wait for the disk with slow metadata creation to complete the creation before the read-write request can be recovered, so that the blocked time of the read-write request of the whole plurality of disks is increased.

As can be seen from the above description, in the prior art, additional machine resources and maintenance costs are required when creating disk data; in the process of creating, an additional synchronization module is used for transferring the disk to a mode of synchronously transferring read-write requests, so that the performance of the disk is obviously reduced; in the whole creating process, a plurality of disks are required to stop reading and writing requests together, snapshot metadata are created together, and the reading and writing requests are restored together, and the disk with the slower creating speed can prevent the disk with the faster creating speed from immediately restoring the reading and writing requests to the storage system, so that the read and writing limited time length of the whole batch of disks is increased, for example, the read and writing limited time length of a single disk is longer than that of a single disk when a snapshot is created asynchronously.

In order to overcome the defects of the above solutions, embodiments of the present invention provide a disk snapshot creating method, which removes an IO synchronous transfer module set in a multi-disk synchronous snapshot creating system, thereby simplifying a system architecture, avoiding generating additional resource consumption and maintenance cost, and improving disk performance; each disk independently creates the snapshot, so that the condition that the limited duration of disk reading and writing is prolonged because the reading and writing requests can be recovered only after all the disks complete the creation of the snapshot does not exist, and the efficiency of creating and completing the disk snapshot is improved.

The disk snapshot creating method according to the embodiment of the present invention is described in detail below with reference to fig. 4 to 6.

Fig. 4 is a schematic structural diagram of a disk snapshot creation system according to an embodiment of the present invention. As shown in fig. 4, in one embodiment, the disk snapshot creation system may include a management and control module and a plurality of disks, such as cloud disk 1, cloud disk 2, … …, cloud disk N.

In one embodiment, the management and control module may be configured to trigger a request for creating a snapshot synchronously; the plurality of disks respond to the request for creating the snapshot synchronously to achieve synchronous snapshot creation.

In one embodiment, the governing module may be a computing node with independent computing and processing capabilities. As an example, the management and control module may include a central processing unit, and the management and control module may run in the same server as the snapshot storage system, or may run in a different server from the snapshot storage system, independently from the snapshot storage system.

In one embodiment, the management and control module may be coupled to the plurality of disks via a communication network. And in the description of the embodiments of the invention, a plurality may mean 1 or more.

Fig. 5 shows a flowchart of a disk snapshot creation method according to an exemplary embodiment of the present invention. As shown in fig. 5, in one embodiment, a disk snapshot creation method may include:

in step S501, the management and control module starts to create a synchronous snapshot for a plurality of disks, for example, disks 1 to N.

Step S502, setting a synchronization initiation waiting time for the plurality of disks.

In this step, the synchronization initiation waiting time may be set empirically, and for the convenience of description, it is assumed that the duration of the synchronization initiation waiting time is t seconds.

Step S503, the management and control module obtains a current timestamp T;

step S504, the management and control module sends a snapshot creation command to the plurality of disks, so that the plurality of disks start to create a snapshot at a time point T + T.

In step S505, the plurality of disks receive the create command, where the create command is used to indicate that each disk will start creating a snapshot at time point T + T.

In this step, the management and control module may decide to have the plurality of disks start creating the snapshot at a time point, such as the current time plus 5 seconds. And issuing a creation command to a plurality of disks, and waiting for the respective creation of snapshots of the disks according to planned time points.

Step S506, each disk waits until the time point of T + T according to the time stamp of the current day.

Step S507, the disk blocks the disk read-write request, and records a time point when the disk read-write request is blocked.

As an example, a point in time X is recorded, for example, at which disk read and write requests are blocked.

Step S508, after the disk read-write request is blocked by each disk, snapshot metadata is created.

In step S509, the creation of the snapshot metadata is completed, and each disk returns the recorded time point X of the blocking disk read-write request to the management and control module.

In this step, multiple disks, e.g., N disks, report the point in time when the IO block started when the snapshot was created, respectively.

Step S510, each disk block transmits the created disk snapshot metadata to the snapshot storage system.

Step S511, the management and control module waits for the creation of the disk snapshots to be completed, and waits for time points of multiple disk blocking read-write requests for the current creation command returned by the disks.

Step S512, determining whether the maximum time difference between the time points of the multiple blocked disk read/write requests is smaller than a set time difference threshold M.

Step S513, when the maximum time difference between the time points of the multiple blocked disk read-write requests is greater than or equal to the set time difference threshold M, determining that the synchronization precision requirement is not met, and deleting the multiple snapshot data transmitted to the snapshot storage system.

Step S514, when the maximum time difference among the time points of the multiple blocked disk read-write requests is smaller than the set time difference threshold value M, the requirement of synchronization precision is determined to be met, and the synchronization snapshot is successfully established.

As an example, assuming that the number of disks is 5, i.e., N takes a value of 5, there are 5 disks to synchronously create a snapshot. The management and control find that the current time point is 13 hours, 05 minutes and 03 seconds, and a snapshot is created after 5 seconds are planned; and sending a creating command to the disks 1 to 5 according to the planned time length.

In this example, the disks 1 to 5 wait for 13 hours, 05 minutes and 08 seconds respectively, start blocking the IO request, and create a snapshot; and respectively informing the management and control module of the timestamp of the disk IO blocking request when the 5 snapshots of the disks 1 to 5 are successfully created. Assume that the timestamps of blocking disk IO requests from disk 1-disk 5 include:

13:05:08.145；

13:05:08.487；

13:05:08.098；

13:05:08.253；

13:05:08.313；

the difference between the maximum timestamp and the minimum timestamp between the timestamps of the blocking disk IO requests is 487-98-389 milliseconds, and if the set time difference M of the synchronization precision requirement is 500 milliseconds, the 5 snapshots meet the requirement, and the creation of the synchronization snapshot is regarded as successful.

Compared with the prior art, the disk snapshot creating method of the embodiment of the invention simplifies the architecture module of the disk fast creation system, omits the IO synchronous transfer module set in the disk fast creation system in the prior art, and avoids additional resource consumption and cost.

In the embodiment, each disk independently creates the snapshot, the read-write request does not need to be transferred to the synchronization module first, and the performance bottleneck of the synchronization module does not exist naturally.

Because each disk independently creates a snapshot and can restore the read-write of the disk per se after the creation is finished, the situation that the read-write can be restored only when the disk with high snapshot creation speed needs to finish the creation of the disk with low snapshot creation speed can not occur.

According to the disk snapshot creating method provided by the embodiment of the invention, the management and control module compares a plurality of blocking time points of a plurality of received blocking disk read-write requests, and if the time difference between the blocking time points meets the set threshold of the synchronous snapshot (for example, the time difference is less than 0.5 second), the plurality of snapshots created at this time are considered to meet the requirement of synchronous precision, and the creation of the synchronous snapshot can be regarded as successful. Otherwise, the N snapshots are deleted and then the creation is retried again.

In the embodiment of the present invention, a public cloud system corresponding to a cloud server and a cloud storage system, such as a cloud disk and a snapshot storage system, generally uses a Network Time Protocol (NTP) to maintain Time clock consistency with each other. In addition, under the normal state, the time consumption of blocking the read-write request by each disk is basically consistent.

Therefore, the disk snapshot creating method in the embodiment of the invention can simplify the engineering implementation of the disk snapshot creating system and can achieve better synchronization precision. If one synchronous creation can realize that the time difference between a plurality of blocking time points is 0.5 second, the new creation time point can be drawn up repeatedly for a plurality of times so as to further reduce the time difference between the plurality of blocking time points, such as 0.1 second, and improve the synchronous creation precision.

FIG. 6 shows a flow diagram of a disk snapshot creation method according to one embodiment of the invention. FIG. 6 illustrates that, in one embodiment, a disk snapshot creation method 600 may include:

step S610, sending a snapshot creating command, where the snapshot creating command is used to indicate time points at which the plurality of disks create snapshots.

Step S620, for the snapshot creation command, receives multiple blocking time points from the multiple disk read/write requests in the process of creating snapshots.

Step S630, when the maximum value of the time difference between the multiple blocking time points is smaller than the set first time difference threshold, determining that the snapshots created by the multiple disks meet the requirement of synchronization accuracy, and obtaining multiple snapshots created by the multiple disks synchronously.

According to the disk snapshot creating method provided by the embodiment of the invention, the management and control module can analyze and judge whether the creating time of the plurality of snapshots meets the requirement of the synchronization precision on the service or not through the received IO blocking time in the snapshot creating process. The whole creating process does not need to rely on a synchronization module in advance to ensure read-write synchronization, and only needs to carry out verification of synchronization precision according to IO blocking time difference among multiple disks after creating the snapshot, so that the system architecture is simpler, and a new module does not need to be introduced, thereby avoiding bringing extra performance degradation problem to the disks, avoiding the problem that the IO blocking time for creating the snapshot is more than that of a single-disk snapshot, and ensuring the IO performance of the disks.

In an embodiment, step S610 may specifically include:

step S611, setting a synchronous waiting duration, where the synchronous waiting duration is used to indicate a waiting duration before the plurality of disks create the snapshot;

step S612, generating a snapshot creating command according to the waiting time before creating the snapshot;

step S613, a snapshot creation command is sent.

In this embodiment, the management and control module may set a synchronous waiting time length for creating the snapshot for the plurality of disks based on a clock consistent with the disks, so that the disks start to create the snapshot after the synchronous waiting time length, and the time precision of the synchronous creation is ensured.

In an embodiment, step S610 may specifically include:

step S614, setting a synchronous creating time point, wherein the synchronous creating time point is later than the current time point;

step S615, according to the synchronous creating time point, generating a snapshot creating command;

in step S616, a snapshot creation command is sent.

In this embodiment, the management and control module may directly set the synchronous creation time point, so that each disk creates the snapshot at the synchronous creation time point according to the synchronous creation time point. Since multiple disks can be based on clocks consistent with the disks, the time accuracy of synchronous creation is guaranteed.

In an embodiment, step S630 may specifically include:

step S631, calculating a maximum value of a time difference between the plurality of blocking time points using a maximum value of the blocking time points and a minimum value of the blocking time points among the plurality of blocking time points;

step S632 is executed to determine that the snapshots created by the multiple disks synchronously meet the requirement of synchronization precision when the maximum time difference is smaller than the set first time difference threshold.

In this embodiment, by recording IO blocking time in the snapshot creation process, whether creation time of multiple snapshots meets a synchronization precision requirement on a service is analyzed and judged, and the multiple disk snapshots are obtained.

In one embodiment, the disk snapshot creation method 600 may further include:

step S640 is to send a new snapshot creating command when the maximum time difference is greater than or equal to the set first time difference threshold, where the new snapshot creating command is used to instruct the multiple disks to synchronously create a new time point of the snapshot after receiving the snapshot creating command.

In one embodiment, the disk snapshot creation method 600 may further include:

step S650, when the maximum value of the time difference is smaller than the first time difference threshold, sending a new snapshot creating command until the maximum value of the new time difference is smaller than a second time difference threshold, and obtaining a plurality of new snapshots created by the plurality of disks synchronously, where the second time difference threshold is smaller than the first time difference threshold.

In this embodiment, because the consistency of the clocks used between the disks is high, the time consumption of blocking read-write requests between the disks is basically consistent, and by regularly creating snapshots for many times, the time difference between multiple blocking time points can be gradually reduced, so that the creation time difference between the disks is smaller and smaller, and the consistency between multiple snapshots created synchronously is higher and higher.

By the disk snapshot creating method, on the basis of not adding an additional module, the IO blocking time in the snapshot creating process is recorded, whether the creating time of the multiple snapshots meets the requirement of synchronous precision on business is judged, and the method has high calculation efficiency on the premise of low resource consumption and cost and no influence on the read-write performance of the disk.

Fig. 7 illustrates a disk snapshot creation method according to another embodiment of the present invention. As shown in fig. 7, in an embodiment, a disk snapshot creating method 700 may specifically include:

step S710, receiving a snapshot creating command, wherein the snapshot creating command is used for indicating a time point for creating a snapshot;

step S720, when waiting to the time point of creating the snapshot, creating disk snapshot data, and transmitting the snapshot data to a snapshot storage system;

step S730, recording a blocking time point when a disk read-write request is blocked in the process of creating disk snapshot data aiming at a snapshot creating command;

step S740, sending the blocking time points, so that the management and control node determines whether the created snapshot data meets the requirement of synchronization precision based on the received multiple blocking time points.

In the embodiment, each disk responds to the snapshot creating command, the snapshot is created independently, the IO request of each disk can be recovered automatically after the creation is completed, the condition that the disk with the high snapshot creating speed can recover the IO only after the disk with the low snapshot creating speed is completed does not exist, and the disk IO capacity is guaranteed to the great extent.

In an embodiment, step S720 may specifically include:

the snapshot creating command comprises the synchronous waiting time length, and the time point of creating the snapshot of the disk is determined according to the current time point of the disk and the synchronous waiting time length; wait until the point in time of the disk at which the snapshot was created.

In this embodiment, the disk may wait according to the synchronous waiting duration, and after the synchronous waiting duration is reached, the snapshot is created, so that the snapshot is created synchronously between the disks.

In an embodiment, step S720 may specifically include:

and when the snapshot creation command comprises the set synchronous creation time point, waiting from the current time point of the disk to the set synchronous creation time point.

In this embodiment, the disk can create a snapshot at a certain timing according to the synchronous creation time point, so as to achieve synchronous creation of snapshots between disks. And a network time protocol is used between the disks to maintain the time clock consistency of the disks, so that the synchronous creation of snapshots between the disks is ensured.

Fig. 8 is a schematic structural diagram of a disk snapshot creating apparatus according to an embodiment of the present invention. As shown in fig. 8, the disk snapshot creating apparatus 800 may include:

a creating command sending module 810, configured to send a snapshot creating command, where the snapshot creating command is used to indicate a time point when a snapshot is created by multiple disks.

A block time receiving module 820, configured to receive, for the snapshot creation command, multiple block time points at which read and write requests of the disk are blocked in the process of creating the snapshot by multiple disks.

The synchronization precision determining module 830 is configured to determine that snapshots created by multiple disks meet a synchronization precision requirement when a maximum value of time differences between multiple blocking time points is smaller than a set first time difference threshold, so as to obtain multiple snapshots created by multiple disks synchronously.

In one embodiment, the create command sending module 810 may include:

the device comprises a waiting time length setting unit, a snapshot creating unit and a snapshot creating unit, wherein the waiting time length setting unit is used for setting synchronous waiting time lengths which are used for indicating the waiting time lengths before the snapshots are created by a plurality of disks;

the first command generating unit is used for generating a snapshot creating command according to the waiting time before creating the snapshot;

and the first command sending unit is used for sending the snapshot creation command.

In one embodiment, the create command sending module 810 may include:

a creation time setting unit for setting a synchronization creation time point later than the current time point;

a second command generating unit for creating a command generating unit for generating a snapshot creating command according to the synchronous creating time point;

and the second command sending unit is used for sending the snapshot creation command.

In one embodiment, the synchronization accuracy determination module 830 includes:

a time difference calculation unit for calculating a maximum value of time difference between the plurality of blocking time points using a maximum value of the blocking time points and a minimum value of the blocking time points among the plurality of blocking time points;

and the synchronization precision judging unit is used for determining that the snapshots synchronously created by the multiple disks meet the synchronization precision requirement when the maximum time difference value is smaller than the set first time difference threshold value.

In an embodiment, the creating command sending module 810 may be further configured to:

and when the maximum time difference value is greater than or equal to the set first time difference threshold value, sending a new snapshot creating command, wherein the new snapshot creating command is used for indicating a plurality of disks to synchronously create a new time point of the snapshot after receiving the snapshot creating command.

and when the maximum time difference value is smaller than the first time difference threshold value, sending a new snapshot creating command until the maximum time difference value is smaller than a set second time difference threshold value, and obtaining a plurality of new snapshots created by the plurality of disks synchronously, wherein the second time difference threshold value is smaller than the first time difference threshold value.

Fig. 9 is a schematic structural diagram of a disk snapshot creating apparatus according to an embodiment of the present invention. As shown in fig. 9, the disk snapshot creating apparatus 900 may include:

a creating command receiving module 910, configured to receive a snapshot creating command, where the snapshot creating command is used to indicate a time point when a snapshot is created.

The snapshot data creating module 920 is configured to create disk snapshot data when waiting for a time point when a snapshot is created, and transmit the snapshot data to the snapshot storage system.

The blocking time recording module 930 is configured to record, for the snapshot creation command, a blocking time point when the disk read-write request is blocked in the process of creating the disk snapshot data.

A blocking time sending module 940, configured to send the blocking time points, so that the management and control node determines, based on the multiple blocking time points, whether the created snapshot data meets the synchronization precision requirement.

In an embodiment, the snapshot data creating module 920 is further specifically configured to, when waiting until a time point when the snapshot is created:

It is to be understood that the invention is not limited to the particular arrangements and instrumentality described in the above embodiments and shown in the drawings. For convenience and brevity of description, detailed description of a known method is omitted here, and for the specific working processes of the system, the module and the unit described above, reference may be made to corresponding processes in the foregoing method embodiments, which are not described herein again.

Fig. 10 is a block diagram illustrating an exemplary hardware architecture of a computing device capable of implementing the disk snapshot creation method and apparatus according to embodiments of the present invention.

As shown in fig. 10, computing device 1000 includes an input device 1001, an input interface 1002, a central processor 1003, a memory 1004, an output interface 1005, and an output device 1006. The input interface 1002, the central processing unit 1003, the memory 1004, and the output interface 1005 are connected to each other through a bus 1010, and the input device 1001 and the output device 1006 are connected to the bus 1010 through the input interface 1002 and the output interface 1005, respectively, and further connected to other components of the computing device 1000.

Specifically, the input device 1001 receives input information from the outside, and transmits the input information to the central processor 1003 via the input interface 1002; the central processor 1003 processes input information based on computer-executable instructions stored in the memory 1004 to generate output information, stores the output information temporarily or permanently in the memory 1004, and then transmits the output information to the output device 1006 through the output interface 1005; output device 1006 outputs the output information external to computing device 1000 for use by a user.

In one embodiment, the computing device 1000 shown in fig. 10 may be implemented as a disk snapshot creation system that may include: a memory configured to store a program; and the processor is configured to run the program stored in the memory to execute the disk snapshot creating method described in the above embodiment.

According to an embodiment of the invention, the process described above with reference to the flow chart may be implemented as a computer software program. For example, embodiments of the invention include a computer program product comprising a computer program tangibly embodied on a machine-readable medium, the computer program comprising program code for performing the method illustrated in the flow chart. In such an embodiment, the computer program may be downloaded and installed from a network, and/or installed from a removable storage medium.

The computer instructions may be stored in or transmitted from one computer-readable storage medium to another computer-readable storage medium, e.g., a website, computer, server, or data center, via a wired (e.g., coaxial cable, optical fiber, digital L)) or wireless (e.g., infrared, wireless, website, microwave, etc.) manner, may be transmitted to another website, computer, server, or data center via a solid state medium such as a semiconductor-readable storage medium, a solid state medium such as a floppy disk, a solid state medium such as a semiconductor-readable storage medium, a floppy disk, a magnetic tape, or the like, (e.g., a hard disk-readable storage medium, a magnetic tape, or the like).

The above-described embodiments of the apparatus are merely illustrative, and the units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of the present embodiment. One of ordinary skill in the art can understand and implement it without inventive effort.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A disk snapshot creation method includes:

sending a snapshot creating command, wherein the snapshot creating command is used for indicating the time points of creating snapshots of a plurality of disks;

aiming at the snapshot creating command, receiving a plurality of blocking time points for blocking disk read-write requests in the process of creating snapshots by a plurality of disks;

and when the maximum value of the time difference among the blocking time points is smaller than a set first time difference threshold value, determining that the snapshots created by the disks meet the requirement of synchronization precision, and obtaining the snapshots created by the disks synchronously.

2. The disk snapshot creation method according to claim 1, wherein the sending of the snapshot creation command includes:

setting a synchronous waiting time length, wherein the synchronous waiting time length is used for indicating the waiting time length before the plurality of disks create the snapshots;

generating a snapshot creating command according to the waiting time before creating the snapshot;

and sending the snapshot creating command.

3. The disk snapshot creation method according to claim 1, wherein the sending of the snapshot creation command includes:

setting a synchronous establishing time point, wherein the synchronous establishing time point is later than the current time point;

generating a snapshot creating command according to the synchronous creating time point;

and sending the snapshot creating command.

4. The disk snapshot creating method according to claim 1, wherein the determining that the snapshots created synchronously across the plurality of disks meet the synchronization accuracy requirement when the maximum value of the time difference between the plurality of blocking time points is smaller than a set first time difference threshold value comprises:

calculating a maximum value of a time difference between the plurality of blocking time points by using a maximum value of the blocking time points and a minimum value of the blocking time points;

and when the maximum time difference value is smaller than a set first time difference threshold value, determining that the snapshots synchronously created by the multiple disks meet the requirement of synchronization precision.

5. The disk snapshot creation method of claim 1, further comprising:

and when the maximum time difference value is greater than or equal to a set first time difference threshold value, sending a new snapshot creating command, wherein the new snapshot creating command is used for indicating a plurality of disks to synchronously create a new time point of the snapshot after receiving the snapshot creating command.

6. The disk snapshot creation method of claim 1, further comprising:

when the maximum time difference value is smaller than the first time difference threshold value, sending a new snapshot creating command until the maximum time difference value is smaller than a set second time difference threshold value, and obtaining a plurality of new snapshots created by the plurality of disks synchronously, wherein,

the second time difference threshold is less than the first time difference threshold.

7. A disk snapshot creation method includes:

receiving a snapshot creating command, wherein the snapshot creating command is used for indicating a time point for creating a snapshot;

when the time point of creating the snapshot is waited, creating disk snapshot data, and transmitting the snapshot data to a snapshot storage system;

recording a blocking time point when a disk read-write request is blocked in the process of creating the disk snapshot data aiming at the snapshot creating command;

and sending the blocking time points to enable a management and control node to determine whether the created snapshot data meets the synchronization precision requirement based on the received multiple blocking time points.

8. The disk snapshot creation method of claim 7, wherein the waiting to the point in time of creating the snapshot comprises:

the snapshot creating command comprises a synchronous waiting time length, and the time point of creating the snapshot of the disk is determined according to the current time point of the disk and the synchronous waiting time length;

and waiting until the time point of creating the snapshot of the disk.

9. The disk snapshot creation method of claim 7, wherein the waiting to the point in time of creating the snapshot comprises:

and when the snapshot creation command comprises a set synchronous creation time point, waiting from the current time point of the disk to the set synchronous creation time point.

10. A disk snapshot creation apparatus comprising:

the snapshot creating module is used for sending a snapshot creating command, and the snapshot creating command is used for indicating time points of creating snapshots of the plurality of disks;

a blocking time receiving module, configured to receive, for the snapshot creation command, multiple blocking time points at which read and write requests of the disks are blocked in a process of creating snapshots of the multiple disks;

and the synchronization precision determining module is used for determining that the snapshots created by the multiple disks meet the synchronization precision requirement when the maximum value of the time difference between the multiple blocking time points is smaller than a set first time difference threshold value, so as to obtain the multiple snapshots created by the multiple disks synchronously.

11. A disk snapshot creation apparatus comprising:

a creation command receiving module, configured to receive a snapshot creation command, where the snapshot creation command is used to indicate a time point at which a snapshot is created;

the snapshot data creating module is used for creating disk snapshot data when waiting to the time point of creating the snapshot and transmitting the snapshot data to a snapshot storage system;

a block time recording module, configured to record, for the snapshot creation command, a block time point when a disk read-write request is blocked in a process of creating the disk snapshot data;

and the blocking time sending module is used for sending the blocking time points so that the management and control node determines whether the created snapshot data meets the requirement of synchronization precision based on a plurality of blocking time points.

12. A disk snapshot creation system is characterized by comprising a memory and a processor;

the memory is used for storing executable program codes;

the processor is configured to read executable program code stored in the memory to perform the disk snapshot creation method of any one of claims 1 to 6.

13. A disk snapshot creation system is characterized by comprising a memory and a processor;

the memory is used for storing executable program codes;

the processor is configured to read executable program code stored in the memory to perform the disk snapshot creation method of any one of claims 7 to 9.

14. A computer-readable storage medium, comprising instructions that, when executed on a computer, cause the computer to perform the disk snapshot creation method of any one of claims 1 to 6.

15. A computer-readable storage medium, comprising instructions that, when executed on a computer, cause the computer to perform the disk snapshot creation method of any one of claims 7 to 9.