Cataloging file system-level changes to a source storage between image backups of the source storage

1. A computer-implemented method for cataloging file system-level changes to a

source storage between image backups of the source storage, the method comprising:

obtaining first file system metadata (FSM) associated with a first image backup of the source storage that represents a first point in time;

obtaining second FSM associated with a second image backup of the source storage that represents a second point in time;

identifying a set of blocks that changed in the source storage between the first point in time and the second point in time without performing a full compare of the first image backup and the second image backup;

analyzing the set of blocks, the first FSM, and the second FSM to:

identify hybrid FSM-file content blocks, each of which being a single block that includes FSM in an FSM portion as well as file content in a file content portion, in the set of blocks where file content portions of the hybrid FSM-file content blocks changed; and

identify files to which the changed file content portions belong; and

cataloging the files to which the changed file content portions belong as files and/or directories that changed in the source storage between the first point in time and the second point in time based on the analyzing.

2. The method as recited in claim 1 , wherein the first image backup is a decremental image backup.

3. The method as recited in claim 2 , wherein the obtaining of the first FSM includes reconstructing the first FSM from the decremental image backup and from one or more subsequent image backups of the source storage.

4. The method as recited in claim 2 , wherein the identifying of the set of blocks that changed includes identifying, as being included in the set of blocks that changed, blocks included in a subsequent full image backup that correspond to block positions of blocks included in the decremental image backup.

5. The method as recited in claim 4 , wherein the identifying of the set of blocks that changed further includes identifying, as being included in the set of blocks that changed, blocks that are designated as allocated in a file system block allocation map (FSBAM) of the first FSM but are designated as free in an FSBAM of the second FSM.

6. The method as recited in claim 1 , further comprising cataloging directories that changed in the source storage between the first point in time and the second point in time.

7. The method as recited in claim 1 , wherein the analyzing of the set of blocks, the first FSM, and the second FSM further includes:

identifying file content blocks in the set of blocks; and

identifying the files to which the file content blocks belong, and

the method further includes cataloging the files to which the file content blocks belong as files that changed in the source storage between the first point in time and the second point in time.

8. The method as recited in claim 6 , wherein the analyzing of the set of blocks, the first FSM, and the second FSM further includes comparing the first FSM to the second FSM to identify the files and/or the directories that changed between the first point in time and the second point in time.

9. One or more non-transitory computer-readable media storing one or more programs that are configured, when executed, to cause one or more processors to perform the method as recited in claim 1 .

10. The method as recited in claim 6 , wherein the cataloging of the files and/or the directories that changed includes cataloging the files that were deleted, modified, or created, or some combination thereof; and/or

the cataloging of the directories that changed includes cataloging the directories that were deleted, modified, or created, or some combination thereof.