Granular replication of volume subsets
Data is replicated on a backup node, where the granularity of the replication can be less than a full volume. A data consistency group comprising a subset of data for a volume is defined for a primary node. A set of differences for the data consistency group is sent to a backup node. The backup node creates change logs in response to receiving the set of differences. In response to receiving a request to access a file having data in the data consistency group, the backup node creates a clone of the file. The backup node determines whether an update to a data block of the file exists in the change logs. In response to determining that the update to the data block exists in the change logs, the backup node updates a copy of the data block for the cloned file with data in the change logs.
1. A method comprising:
in response to receiving a request to access a requested version of a file, identifying backup data of the file that corresponds to a version of the file different than the requested version;
identifying a set of updates within a change log that correspond to differences between the version of the file and the requested version;
applying the set of updates to a clone of the file to create a modified cloned file corresponding to the requested version of the file targeted by the request;
modifying a mapping of the cloned file to remap a file block number from being mapped to a first block number to being mapped to a second block number corresponding to changed data applied by the set of updates to the cloned file; and
executing the request upon the modified cloned file utilizing the modified mapping.
2. The method of claim 1 , wherein the requested version is a newer version than the version of the file represented by the backup data.
3. The method of claim 1 , wherein the applying excludes updates within the change log corresponding to non-requested versions of the file.
4. The method of claim 1 , wherein the requested version is an older version than the version of the file represented by the backup data.
5. The method of claim 1 , wherein the cloning comprises:
creating the cloned file and associating data blocks of the cloned file with corresponding data blocks of the file.
6. The method of claim 1 , wherein the request to access the file includes a version identifier of the requested version.
7. The method of claim 6 , wherein the method further comprises:
identifying the change log from a set of change logs based upon the change log corresponding to the version identifier.
8. An apparatus comprising:
a processor; and
a machine readable storage medium having machine executable code stored therein that is executable by the processor to cause the apparatus to:
in response to receiving a request to access a requested version of a file, identify backup data of the file that corresponds to a version of the file different than the requested version;
identify a set of updates within a change log that correspond to differences between the version of the file and the requested version;
apply the set of updates to a clone of the file to create a modified cloned file corresponding to the requested version of the file targeted by the request;
modify a mapping of the cloned file to remap a file block number from being mapped to a first block number to being mapped to a second block number corresponding to changed data applied by the set of updates to the cloned file; and
execute the request upon the modified cloned file utilizing the modified mapping.
9. The apparatus of claim 8 , wherein the requested version is a newer version than the version of the file represented by the backup data.
10. The apparatus of claim 8 , wherein the applying excludes updates within the change log corresponding to non-requested versions of the file.
11. The apparatus of claim 8 , wherein the requested version is an older version than the version of the file represented by the backup data.
12. The apparatus of claim 8 , wherein the machine executable code causes the processor to:
create the cloned file and associating data blocks of the cloned file with corresponding data blocks of the file.
13. The apparatus of claim 8 , wherein the request to access the file includes a version identifier of the requested version.
14. The apparatus of claim 13 , wherein the machine executable code causes the processor to:
identify the change log from a set of change logs based upon the change log corresponding to the version identifier.
15. A non-transitory machine readable medium having stored thereon instructions comprising machine executable code which when executed by a machine, cause the machine to:
in response to receiving a request to access a requested version of a file, identify backup data of the file that corresponds to a version of the file different than the requested version;
identify a set of updates within a change log that correspond to differences between the version of the file and the requested version;
apply the set of updates to a clone of the file to create a modified cloned file corresponding to the requested version of the file targeted by the request;
modify a mapping of the cloned file to remap a file block number from being mapped to a first block number to being mapped to a second block number corresponding to changed data applied by the set of updates to the cloned file; and
execute the request upon the modified cloned file utilizing the modified mapping.
16. The non-transitory machine readable medium of claim 15 , wherein the requested version is a newer version than the version of the file represented by the backup data.
17. The non-transitory machine readable medium of claim 15 , wherein the applying excludes updates within the change log corresponding to non-requested versions of the file.
18. The non-transitory machine readable medium of claim 15 , wherein the requested version is an older version than the version of the file represented by the backup data.
19. The non-transitory machine readable medium of claim 15 , wherein the instructions further include instructions to:
create the cloned file and associating data blocks of the cloned file with corresponding data blocks of the file.
20. The non-transitory machine readable medium of claim 15 , wherein the request to access the file includes a version identifier of the requested version.