# US 2021/0240578 A1 · Data backup method, apparatus, and system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0240578 A1 - Document ID: US20210240578A1 - Status: Published application - Kind: A1 - Application number: 17/235,557 - Filed: 2021-04-20 - Published: 2021-08-05 - Earliest claimed: 2018-10-22 - Assignees: Huawei Technologies Co., Ltd. - Applicants: Huawei Technologies Co., Ltd. - Inventors: Lei Zhang - Web page: https://patentgrep.com/patent/US20210240578A1 ## CPC - G06F 11/1464: {for networked environments} - G06F 11/1435: {using file system or storage system metadata} - G06F 11/1451: {by selection of backup contents} - G06F 11/1453: {using de-duplication of the data} - G06F 11/1458: {Management of the backup or restore process} - G06F 11/1466: {to make the backup process non-disruptive} - G06F 11/1469: {Backup restoration techniques} - G06F 2201/84: Using snapshots, i.e. a logical point-in-time copy of the data - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) ## Abstract In a data backup method, after data backup is triggered, a backup server sends a change information obtaining request to a file server to request change information of data on the file serve. The backup server receives a data change record returned by a file server, wherein the data change record comprises identification information of a changed data block. The backup server then obtains data according to the data change record, backs up the obtained data, and establishes a data mapping relationship for the current backup. When data of a backup needs to be obtained, data of a corresponding data block is found in the backup storage device according to the data mapping relationship. ## Claims ### Claim 1 A data backup method performed by a backup server, comprising: after a data backup operation is triggered, sending a change information obtaining request to a file server to request for change information of data in the file server; receiving, from the file server, a record of a data change between a second snapshot and a first snapshot made before the second snapshot, wherein the data change record records information about a data block corresponding to the change between the second snapshot and the first snapshot, and the data change record includes identification information of the data block corresponding to the changed; obtaining, from the file server based on the data change record, data in the data block identified by the identification information of the data block; storing the obtained data in a backup storage device; and establishing a data mapping relationship for the backup operation, where the data mapping relationship includes identification information of all data blocks in the second snapshot, storage locations of all the data blocks in the second snapshot in the backup storage device, and a snapshot identifier of the second snapshot. ### Claim 2 (depends on 1) The method according claim 1, wherein the data change record further includes a corresponding operation identifier, and the step of establishingthe data mapping relationship comprises: copying a data mapping relationship established during a previous backup into the backup storage device; and modifying the copied data mapping relationship based on the data change record, to obtain the data mapping relationship for this backup. ### Claim 3 (depends on 1) The method according to claim 1, wherein before the step of sending the change information obtaining request to the file server, the method further comprises: sending a snapshot request to the file server; and receiving a snapshot creation success response returned by the file server, where the response comprises the snapshot identifier of the second snapshot. ### Claim 4 (depends on 1) The method according to claim 1, wherein the file server and the backup storage device are heterogeneous. ### Claim 5 (depends on 1) The method according to claim 1, wherein the change information obtaining request comprises the snapshot identifier of the second snapshot and a snapshot identifier of the first snapshot. ### Claim 6 (depends on 1) The method according to claim 1, further including: storing the data mapping relationship in the backup storage device. ### Claim 7 (depends on 1) The method according to claim 1, wherein the identification information of the data block comprises a data block identifier and a file identifier of a file including the data block. ### Claim 8 A data backup method performed by a file server, comprising: receiving, from a backup server, a change information obtaining request requesting for change information of data in the file server; determining the change information of the data in the file server; returning a record of a data change between a second snapshot and a first snapshot to the backup server, wherein the first snapshot is created before the second snapshot, the data change record is used to record information about a data block corresponding to the change between the second snapshot and the first snapshot, and the data change record includes identification information of the changed data block; receiving a data obtaining request sent by the backup server, wherein the data obtaining request includes identification information of a to-be-obtained data block; and returning, to the backup server, data in the data block identified by the identification information of the data block. ### Claim 9 (depends on 8) The method according to claim 8, further comprising: tracking a data operation performed by a client on the file server; and recording a record of a data change between two adjacent snapshots, where the record of the data change between the two adjacent snapshots includes identification information of a data block corresponding to the change between the two adjacent snapshots. ### Claim 10 (depends on 9) The method according to claim 9, wherein the second snapshot and the first snapshot are not adjacent snapshots, and wherein the method further comprises: obtaining the record of the data change between the second snapshot and the first snapshot by combining records of data changes between every two adjacent snapshots between the second snapshot and the first snapshot. ### Claim 11 A backup server comprising: a network interface for accessing a network; a memory storing executable instructions; a processor configured to execute the executable instructions to: after a data backup operation is triggered, send a change information obtaining request to a file server to request for change information of data in the file server; receive from the file server, a record of a data change between a second snapshot and a first snapshot taken before the second snapshot, wherein the data change record records information about a data block corresponding to the change between the second snapshot and the first snapshot, and the data change record includes identification information of the data block corresponding to the changed data; obtain, from the file server based on the data change record, data in the data block identified by the identification information of the data block; store the obtained data in a backup storage device; and establish a data mapping relationship for this backup, where the data mapping relationship includes identification information of all data blocks in the second snapshot, storage locations of all the data blocks in the second snapshot in the backup storage device, and a snapshot identifier of the second snapshot. ### Claim 12 (depends on 11) The backup server according to claim 11, wherein the data change record further comprises a corresponding operation identifier, and the instructions further cause the backup server to be configured to: copy a data mapping relationship established during a previous backup into the backup storage device, and modify the copied data mapping relationship based on the data change record, to obtain the data mapping relationship for this backup. ### Claim 13 (depends on 11) The backup server according to claim 11, wherein the instructions further cause the backup server to be configured to: send a snapshot request to the file server; and receive a snapshot creation success response returned by the file server, where the response includes the snapshot identifier of the second snapshot. ### Claim 14 A file server comprising: a network interface for accessing a network; a memory storing executable instructions; and a processorconfigured to execute the executable instructions to: receive, from a backup server, a change information obtaining request requesting for change information of data in the file server; determine the change information of the data in the file server; return a record of a data change between a second snapshot and a first snapshot to the backup server, wherein the first snapshot is created before the second snapshot, the data change record is used to record information about a data block corresponding to the change between the second snapshot and the first snapshot, and the data change record includes identification information of the changed data block; receive a data obtaining request sent by the backup server, wherein the data obtaining request includes identification information of a to-be-obtained data block; and return, to the backup server, data in the data block identified by the identification information of the data block. ### Claim 15 (depends on 14) The file server according to claim 14, wherein the instructions further cause the file server to be configured to: track a data operation performed by a client on the file server; and record a record of a data change between two adjacent snapshots, where the record of the data change between the two adjacent snapshots includes identification information of a data block corresponding to the change between the two adjacent snapshots. ### Claim 16 (depends on 15) The file server according to claim 15, when the second snapshot and the first snapshot are not adjacent snapshots, and the instructions further cause the file server to be configured to: obtain the record of the data change between the second snapshot and the first snapshot by combining records of data changes between every two adjacent snapshots between the second snapshot and the first snapshot. ### Claim 17 (depends on 11) A backup system, wherein the backup system comprises the backup server according to claim 11 and a file server according to 14. ### Claim 18 (depends on 17) The backup system according to claim 17, wherein the backup system further comprises a backup storage device, wherein the backup storage device is configured to store data sent by the backup server.