A method for excavating of continuous snapshots in a computer file system and corresponding computer readable storage medium

Abstract

A method for version capture of continuous snapshots of a computer file system and a computer-readable storage medium are provided. The method includes the following steps: establishing a Continuous Snapshot Log System (CSNAP Diary) to collect continuous snapshots of computer files within a specific period and saving the root block pointer of the transaction group to record the state of the data management node (dnode) and data block at the time of snapshot generation; adding two fields to the data management node to identify the start and end values ​​of each modification; when the data management node is modified in different transaction groups, dynamically setting the start and end values ​​according to the conditions of adjacent or non-adjacent transaction groups to accurately record the range of changes; the method achieves rapid version capture by traversing the minimum value of the start and end values ​​marked in the data management node and tracing back all modified versions of the files from the last continuous snapshot.

Claims

1. A method for version capture of continuous snapshots of a computer file system, comprising the following steps: Establishing a Continuous Snapshot Log System (CSNAP Diary) to collect continuous snapshots of the computer file system within a specific period; Creating the continuous snapshot of the computer file system, each continuous snapshot corresponding to a transaction group with a strictly increasing sequence number, and saving the root index block of the transaction group, the root index block pointing to the status of all data management nodes and data blocks of all computer files at the time corresponding to the continuous snapshot; Setting two fields in the data management node (dnode) of an individual computer file, representing the start value and the end value respectively; When the data management node of the computer file is created in the Nth transaction group, setting the start value to N and the end value to an identifiable numerical value; When the data management node of the computer file is modified in the Nth transaction group, and its previous modification was in the Mth transaction group, if N is the next adjacent transaction group after M, then changing the end value to N, while keeping the start value unchanged; otherwise, changing the start value to N and setting the end value to M; For each transaction group, for the starting and ending values ​​of the data management node of the computer file corresponding to the last continuous snapshot time point, starting from the data management node of the computer file corresponding to the last continuous snapshot, repeat the following operation to obtain the file version information corresponding to the data management nodes of all modified computer files: Define the current transaction group as the operation transaction group. If the ending value of the data management node of the computer file corresponding to the continuous snapshot of the operation transaction group is equal to the identifiable value, then end the operation; If the starting value of the data management node of the computer file corresponding to the continuous snapshot of the operation transaction group is less than the ending value, then list all transaction groups with the sequence number within the interval from the starting value to the ending value, and find the transaction group with the sequence number equal to the starting value, define it as the starting transaction group, check the continuous snapshots corresponding to the starting transaction group, and define the ending value of the data management node of the corresponding computer file as the starting and ending values, then find the transaction group with the sequence number equal to the starting and ending values ​​and continue the operation; If the starting value of the data management node of the computer file corresponding to the continuous snapshot of the operation transaction group is greater than the ending value, then list the transaction groups with the sequence number equal to the starting value, and jump to the transaction group with the sequence number equal to the ending value to continue the operation.

2. The method according to request item 1, wherein, The specific period refers to a period specified by the user.

3. The method according to request item 1 or 2, wherein, This continuous snapshot is an additional snapshot system created outside of the native snapshot system of the general file system, used to record continuous snapshots.

4. The method according to request item 3, wherein, The general file system refers to any file system that uses transaction groups.

5. The method according to request item 1 or 2, wherein, The continuous snapshot refers to an additional snapshot created in addition to the native snapshot of the general file system. The time interval between each snapshot is shorter than that between the native snapshots of the general file system, and can be freely determined by the user.

6. The method according to request item 1 or 2, wherein, The start value and the end value refer to a pair of values ​​that do not specify the data type.

7. The method according to request item 1 or 2, wherein, The identifiable value includes 0.

8. The method according to request item 1 or 2, wherein adjacent transaction groups comprise two transaction groups whose difference in sequence number and / or write time difference is less than a specific value.

9. The method according to claim 1 or 2, wherein, The starting transaction group includes the next adjacent transaction group whose starting value is less than the ending value.

10. The method according to claim 1 or 2, wherein, It obtains the file version information corresponding to the data management node of all modified computer files, including providing a standard file reading interface to facilitate operation by users using familiar file management or visualization software.

11. A computer-readable storage medium storing a plurality of instructions, which are read by an electronic device to perform a method for continuously capturing versions of a computer file system as described in any one of claims 1 to 10.

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